Best Low Profile Box Springs 2021 – Buyer’s Guide & Reviews

Low Profile Mattress FoundationA good bed is important for good sleep and you may need a best low profile box spring to make a bed good. If you are looking for the best low, ultra-low or thin box springs to make a good bed, that guide might help you.

We spend lots of hours to create a list of the best low profile box springs, so I hope you will enjoy this list and buyer’s guide. Let’s continue.

Comparison Table

We have selected top products and written the review on them which can help you. First check the list of top products below.

Last update on 2023-05-15 / Affiliate links / Information including Images from Amazon Product Advertising API

10 Best Low Profile Box Springs Review

Before going to the review section, let’s check a video from our YouTube page overview below, from there you can get the overall idea of the products.

Classic Brands Instant Foundation Low Profile 4” Box-Spring Replacement

Product Specification (For Queen Size):

  • Material: Solid Spruce
  • Available Sizes: Twin, Twin XL, Full, Full XL, Queen, King, California King
  • Assembled Height: 4 inches
  • Assembled Width: 59.5 inches
  • Assembled Length: 79 inches
  • Weight: 53.5 Pounds
  • Easy to Assemble: Yes

One of the best box spring for memory foam mattress from Classic Brands. The assembly process is fast and easy enough, especially when you use an electric screwdriver. When it’s assembled well, its frame and slats are strong, sturdy and solid enough, too, but you may want to avoid using your bed as a mini-trampoline. You may notice noises occasionally but it isn’t a big issue.

The bed foundation can support a fairly heavy mattress, such as a thick latex or memory foam mattress, while also preventing its premature sagging on the middle and sides. Keep in mind, too, that it will not make your mattress firmer or softer since it’s a support base, not a topper and the like.

According to the manufacturer, the box spring replacement is made of solid spruce that has been handcrafted by the Pennsylvania Amish. The implication here is that it’s an American product with guaranteed quality.


  • Ready for assembly with all tools and parts needed already in the package
  • Solid construction and quality
  • Made of durable spruce


  • Reinforcement may be needed to make it last longer
  • Rough corners (i.e., sanding can remove the rough parts)
Shop now at

Zinus 4 Inch Low Profile BiFold Box Spring With Strong Steel structure

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Steel
  • Available Sizes: Twin, Full, Queen, King, Cal King
  • Assembled Height: 4 inch
  • Dimensions: 79 x 59.5 x 4 inches
  • Weight: 34.6 pounds
  • Easy to Assemble: No Assembly Required.

Yet another Zinus low profile split box spring that doesn’t require assembly is this 4-inch bi-fold box spring (What is Bi-Fold Box Spring). You just open its box, slide-out its foundation, and then unfold it and voila! You have a metal box spring that can be used immediately.

The folding design also makes it easy and convenient to carry between bedrooms and store in the attic, in case it isn’t needed yet.  You don’t have to worry that it may split down the middle, especially with heavy movements from children and pets, because of the strong metal foundation.

The steel foundation may initially look heavy but it’ surprisingly lighter than expected. You can, however, place a thick mattress of any type on top of it yet it will hold the weight, plus a few other people.


  • Comes with a 5-year limited warranty
  • Ideal height for people who want to sleep closer to the floor
  • No assembly needed
  • Strong and sturdy frame


  • Actual height is 4.5 inches
  • Not exactly a box spring and more like a foundation
Check Price on Amazon

Zinus 5 Inch Low Profile Smart Box Spring/Mattress Foundation/Strong Steel Structure

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Steel
  • Available Sizes: Twin, Twin XL, Full, Queen, King, Cal King
  • Assembled Height: 5 inch
  • Assembled Width: 59.5 inches
  • Assembled Length: 79 inches
  • Dimensions: 79 x 59.5 x 5 inches
  • Weight: 37.7 pounds
  • Easy to Assemble: Yes

Parents who are worried about broken wooden slats from their children’s energetic jumping on the bed may find the Zinus 5 inch low profile box spring a great choice. The metal slats should hold up against the stress better than wooden slats, not to mention that the box spring may be lighter, too.

The box spring comes in several parts when shipped, said parts of which include the tubular metal pieces, nuts, and screws, and two types of wrenches. There are no detailed written instructions but the illustrated diagram was enough to get the job done within 30 minutes or less.

Once assembled, you just need to put on the box spring’s cover and zip it into place. You can then place the mattress on top of it and follow with the beddings from the sheets to the pillows. You may or may not add a dust ruffle to the bed setup.

The box spring makes most mattresses so much more comfortable to lie on, as well as more supportive. You can pair it with most types of mattresses, such as thick memory foam mattress, but the level of firmness, give and bounce will vary.

Let’s check the pros and cons of this 5-inch box spring below.


  • Easy assembly
  • No noise when properly assembled
  • Can withstand years of use


  • May not be suitable for use with softer mattresses (i.e., the foam can sag into the slats)
Check Price on Amazon

Zinus 4 Inch Low Profile Quick Lock Smart Box Spring With Strong Steel Structure

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Steel
  • Available Sizes: Twin, Full, Queen, King
  • Assembled Width: 4 inch
  • Dimensions: 79 x 59.5 x 4 inches
  • Item Weight: 48.4 pounds
  • Easy to Assemble: Yes

If you are looking for a box spring full low profile then that can be the right choice. This Zinus 4-inch box spring with quick-lock construction is also easy to assemble, even as a one-person job. You don’t have to struggle too much when transferring it from living room to bedroom, thanks to the compact packaging. The necessary tool is already included, along with extra screws.

There are no written instructions but the illustration clearly shows which part goes where, especially the bars, rails, and screws. The metal slates easily pop into their slots, aside from being close together. The slats are spaced evenly at 3 inches apart.

You can use a memory foam mattress with it although other types of mattresses will also be suitable.

You don’t have to worry about the metal slats making too much noise when you’re on top of the mattress. The slats are designed so that there’s little to no metal-on-metal contact resulting in noise elimination.  Your kids and pets can even jump on it and there will be no noise coming from it.

The pros and cons of that 4-inch box spring:


  • The compact packaging and easy assembly
  • Comes in several sizes
  • Durable quality


  • The black metal design may be too modern for some people
Check Price on Amazon

Lifetime Sleep Products 4 Inch – Best Box Spring For Memory Foam Mattress

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Wood
  • Available Sizes: Twin, Twin X-Large, Full, Queen, King
  • Assembled Height: 4 inch
  • Dimensions: 80 x 60 x 4 inches
  • Item Weight: 60 pounds
  • Easy to Assemble: Yes

This one is another good 4-inch box spring. While box springs are traditionally only suitable for innerspring mattresses, the Lifetime Sleep Products box spring can be used for all types of mattresses. You will probably agree that it works well for either a heavy memory foam mattress or a light latex mattress. But it’s still best paired with an innerspring mattress.

You have to be ready for assembling it although it shouldn’t take more than an hour with the appropriate tools. You will likely need screwdrivers for putting in the screws and screw tops for the slats. You may also need a portable cordless drill. Afterward, the cover should be placed over it.

While the assembly may be inconvenient if you want a ready-to-use box spring, it has its merits, too. You can, for one thing, have an easier time carrying the parts of the box spring from your living room to your bedroom. You may even have a better appreciation for its construction.

You can consider this product as a thin box spring as because of the 4-inch height.

Let’s check the pros and cons of this 4-inch low profile box spring below.


  • Easy to assemble and comes with instructions
  • High-quality construction
  • Comes with a cover that can be tightened over the beams


  • Many buyers complained that the dimensions aren’t standard (i.e., 79”x75” instead of 80”x76”)
  • Wooden slats are too far apart (4.5”) for a memory foam mattress
Check Price on Amazon

Continental Sleep Fully Assembled 5 Inch Box Spring for Mattress

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Wood structure
  • Available Sizes: Twin, Twin XL, Full, Queen
  • Assembled Height: 4-inch
  • Dimensions: 75 x 39 x 4 inches
  • Item Weight: 35 pounds
  • Easy to Assemble: Fully assembled

If you are looking for 5-inch box spring, then this product can be perfect for you. Many of the box springs in our list require assembly but it isn’t the case with the Continental Sleep box spring. Just place it in your bedroom, remove the packaging, and place the innerspring mattress on its top and voila!  You should obviously place the sheets and pillows but it’s the easy part.

The 5-inch height is higher than many of the box springs in our list but it still falls in the low profile box spring category. You may also like taller dimension if you neither want a bed that sits too low nor too high from the floor; either one has its issues, too.

While the box spring has a sturdy quality to it in the overall sense, it has its share of issues, unfortunately. You may find that it’s only suitable for people under 60 pounds and it can only be used for a couple of years, at most.

But since it’s an inexpensive box spring anyway, you may overlook the satisfactory quality over the short-term period.

We have summarized the pros and cons of this 5-inch low profile box spring below.


  • No assembly needed
  • Provides a sturdy and supportive platform for an innerspring mattress
  • Affordable price


  • Construction quality isn’t up to par
  • Product may arrive damaged
Check Price on Amazon

Zinus 4 Inch Low Profile Wood Box Spring/Mattress Foundation

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Wood
  • Available Sizes: Twin, Full, Queen, King
  • Assembled Height: 4 Inch
  • Dimensions: 59.5 x 79 x 4 inches
  • Item Weight: 42.9 pounds
  • Easy to Assemble: Yes

The 4-inch height of the Zinus wood box spring makes it the ideal choice for people with physical limitations that make it difficult for them to get on and off the bed easily. But it’s only available in four sizes – twin, full, king, and queen – and it obviously can’t be customized.

This product is one of the thin box spring in the market.

You shouldn’t have an issue getting it from your front door to your bedroom because it’s relatively lightweight. Once in your bedroom, you can remove its plastic cover and assemble it in a specific area where it will be placed.  You should be able to assemble it within 10-15 minutes.

As a wooden low profile box spring, it’s fairly strong and sturdy even when two or more people use the bed set on a regular (i.e., daily naps and nightly sleep) basis. You may even find that it can withstand fairly heavy movements.

But a few of the wooden slats can also become broken after several months so a replacement set will be necessary; no word on whether the company provides the replacement. The trick here is to use a thicker mattress so that heavy movements can be more effectively deflected.

Let’s check the pros and cons of that 4-inch low profile box spring below.


  • Easy to assemble (shipped in five pieces)
  • Strong and sturdy construction
  • Low height


  • Dust cover can be difficult to fit
  • Slats may break after several months
Check Price on Amazon

Zinus Queen 4 inch Thin Box Spring – Metal Box Spring with Wood Slats

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Steel structure with wood slat support
  • Available Sizes: Twin, Twin XL, Full, Queen, King, Cali King
  • Assembled Height: 4 Inch
  • Assembled Width: xxx
  • Assembled Length: xxx
  • Dimensions: 78.9 x 59.7 x 4 inches
  • Item Weight: 49.2 pounds
  • Easy to Assemble: Yes

The Zinus 4 inch box spring queen is so easy to assemble even a non-DIY enthusiast will find it easy-peasy to set up. Even the only tool needed in its assembly – the hex bit – is already included in the package. Getting it to the bedroom is fairly easy, too, thanks to its lightweight.

The combination of metal and wood means that it’s one of the sturdiest box springs in our list. The steel frame ensures that every inch of a properly fitted mattress will not sag at the edges. The foam-padded tape on the steel frame reduces the noise, even with movement.

The wood slats are spaced evenly, as well as designed to provide your mattress with a supportive surface. There’s even non-slip tape on the wood slats, which also reduces the movement of your mattress in all directions.

Overall, you will find that it’s a high-quality low profile box spring measuring just 4 inches in height. You can then pair it with a thick innerspring mattress yet it will still stay as close to the floor as needed.

Let’s check the pros and cons of this 4 inch low profile box spring.


  • Durable box spring with metal frame and wood slats
  • Easy to assemble
  • Comes with a 5-year limited warranty


  • Zipper and cover doesn’t seem so durable
Check Price on Amazon

Continental Sleep Low Profile Box Spring

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Wood structure
  • Available Sizes: Twin, Twin XL, Full, Full XL, Queen, King, Cal King
  • Assembled Height: 4-8 inches
  • Dimensions: 80 x 60 x 4 inches
  • Item Weight: 45 pounds
  • Easy to Assemble: Fully assembled and ready to use

Continental Sleep has put together a low-profile box spring that has been created to provide you with a massive amount of support and alignment as you sleep.

It was designed specifically to work alongside a mattress to ensure you’re able to experience complete support while you sleep. Your whole body feels more aligned, which can reduce any painful pressure points or tight muscles.

They’ve used steel and wood materials to construct it. Not only are they responsible for the supportive base, but they are also incredibly durable. So, you can be sure that you can use this box spring for a while.

There’s an innerspring coil until on the interior, we well as a gauge border and unit. This adds to the rigidity and alignment benefits tremendously.

Heavy-duty fabrics have also been used to make this box spring. This includes stitched layers of bonded fabric as well as Polly foam materials.

There is even a specific layer added on top to ensure that mattresses don’t move around on the box spring.

Customers have also been liking how Continental Sleep has approached the visual design to this box spring. They’ve managed to make it look fantastic with all kinds of mattresses.

In order to make the customers’ experience as smooth as possible, this company delivers the box spring to you in a fully assembled state. As a result, you can simply unbox it and start using it with no delays.


  • Complete support & alignment benefits
  • Great design
  • Heavy-duty materials
  • Anti-skid fabric
  • Delivered fully assembled


  • Feels a little lighter than some were expecting
Shop now at

Kingsdown Passions Box Spring Low Profile

By clicking on the image you can check that product details on Amazon

Product Specification (For Queen Size):

  • Material: Wood and steel
  • Available Sizes: Twin, Full, Full XL, Queen, Split Cal King
  • Assembled Height: 5 inches
  • Dimensions: 80 x 60 x 5 inches
  • Item Weight: 34 pounds

This Passions Low Profile Box Spring from Kingsdown has been created with a fantastic semi-flexed foundation.

We found the materials that are used to construct it are incredibly supportive and durable. They have combined wood and steel to make this box spring. As a result, you can be sure that it will last you for years to come.

Moreover, these materials work to boost the overall stability of the box spring foundation.

It provides you with a very rigid support system. Furthermore, we liked how it works well with mattresses to make sure you have complete support.

To be more specific, this box spring foundation enhances the alignment of your entire body. Your heels, shoulders, hips, and head will all be fully supported while using this box spring.

Customers have also been very appreciative of how Kingsdown has put so much thought into the aesthetic design. This means that you can use many different kinds of mattresses and feel confident in knowing that they will match well with the box spring.

One of the other major benefits that we noticed when ordering this box spring is that it arrives 100% assembled. This will come as a major relief to many people.

Trying to assemble a box spring proves challenging for many people. But that’s not something you need to worry about with this one.


  • Extremely durable materials
  • Incredibly supportive foundation
  • Improves alignment of your entire body
  • Visually appealing
  • Arrives fully assembled


  • May be too thin for some people
  • Rigidity could be too hard for others
Shop now at

Buyer’s Guide

You may have lots of questions on the low profile box springs. We are discussing some basic points below, it might help you. If you have more queries, you can post that in the comment section, we will reply as early as possible.

What is a Low Profile Box Spring?

Best Low Profile Box SpringAlso known as a low profile foundation, a low profile box spring shares several similarities with a standard box spring including its materials, layers, and purpose. The main difference lies in their height – a standard one measures as high as 9 inches while a low profile one measures 5.5 inches.

The relatively significant height difference doesn’t affect the comfort and support that both types of box spring provide for their users. The shorter height is in response to the thicker thicknesses of most mattresses. The combination means that the entire bed sits close to the floor without being a futon.

What is a thin box spring?

A thin box spring, otherwise known as a low-profile box spring, is a thin foundation. They are specifically designed in this way because mattresses nowadays are being manufactured with more thickness than before.

Therefore, a thin box spring doesn’t increase the height of how you sleep in your bed too much further. That’s why, they are a great choice for people who aren’t fans of feeling further away from the ground. They are usually between the sizes of 5-5.5” in height and can support all kinds of mattresses.

What is half box spring?

A half box spring is essentially the same as the thin foundation, apart from one key difference.

It’s taller in height.

A box spring half height will usually measure in at 9”, which is around 4” taller than the thin box springs. There is no difference when it comes to the amount of support provided.

However, they do provide you with a more elevated sleeping position. They can work very well with mattresses of all heights too.

What is a flat box spring?

A flat box spring refers to foundations that are designed with a completely flat surface. Usually, they are constructed with wood materials and accompanied by some kind of board over the top.

Other flat foundations may involve metal as well as wood.

These types of box springs can be used for all kinds of mattresses. These include latex, memory foam, airbed, and innerspring mattresses. The flat surface is beneficial for decreasing the amount of sag that can happen to some mattresses over time.

What is the standard height of low-profile box spring?

A box spring that has a low-profile design is the preferred option for many people.

The main reason for this being that they are a lot lower in height compared to the standard box springs. Therefore, many people find them comfier and easier to sleep on.

They don’t like feeling so high up while trying to sleep. The height of low-profile box springs is usually anywhere between four and six inches.

Available Sizes of Box-Spring

So, you now have a better understanding of what box springs can offer you. However, how do you know which size is best for you?

Generally, the box spring sizes are similar to the standard mattress sizes. For your understanding, we are giving the list below:

A) Twin

A spring twin box spring is the ideal choice for either one adult or child. This is a popular choice among people who have smaller rooms.

B) Twin-XL

A Twin-XL spring box provides you with a little more length than the regular Twin size. Therefore, this one may be more appropriate for adults living in smaller spaces.

C) Full/Full-XL

Box springs that are full or full-XL sizes are best for one person. There is still enough room for a single person to move around comfortably. The full-XL options tend to provide a little more width and length than the Full sizes. The full size also calls double bed box spring.

D) Queen

When it comes to the queen sizes, we find these to be a better option for two adults who prefer sleeping closer together. This is because its dimensions are a little more compact, but still good for supporting two people comfortably.

E) California King

The California King is the largest box spring size available. It is awesome for holding up to two adults while leaving extra room for children and pets.

F) King Sizes

A king-sized box spring is a great option for two people. Similarly, to the California King, there is also some added room available for kids and pets. However, it’s generally not quite as large.

2 Inch Box Spring

During our study on buyers’ demand, we have seen that many people are looking for 2 inch box spring. Unfortunately, in our research, we could not find any box spring in which height is two inches. If you are looking for that size, then I will advise you to take a 4 inches box spring.

Do you need a bed frame if you have a box spring?

You do not need to have a bed frame to use a box spring. Many people like to use only box springs and mattresses together, without a frame. This is a good choice if you’re not too concerned with the aesthetic side. In this case, you can just set up the box spring on the floor and place your mattress on top.

But you can also use box springs with a frame too. It comes down to each individual’s preference.

The Purpose of a Low Profile Box Spring

The Purpose of a Box Spring

A box spring provides strong and sturdy support for the innerspring mattress. The solid and flat surface also ensures that the mattress doesn’t prematurely warp and sag with regular use.

By absorbing the shock placed on the mattress when persons sit or lie down on it, a box spring can also decrease the wear and tear on the mattress. It can even make the mattress more comfortable and supportive so it’s one of the must-have purchases for a great bed.

In a complete bed set, the box spring can be placed on top of the frame that, in turn, will be attached to the footboard and headboard. But there are also instances when a box spring and a mattress are used together sans a complete bed set.

In the case of the latter, the box spring can be placed either on the floor or on casters depending on the desired height. The mattress can then be set on top of it for a comfortable and supportive bed.

Difference Between Low Profile Foundation and Box Spring

A true box spring has two components, namely, wood frame and coils. The coils, also known as springs, are arranged in a steel grid pattern so that these provide the desired “give” to the mattress.

A foundation is a durable flat structure typically made of wood or metal combined with a flat corrugated board on its top. The most common mattresses used for a foundation are latex, memory foam, and airbeds as well as innerspring types. The solid surface provides a sturdy surface for reducing premature sagging.

Difference Between a Low Profile and Standard Box Spring

A high profile box spring, or a standard box spring, is ideal for people who like sleeping higher off the ground. Many people also like it because of its more aesthetic appearance, especially since it can be decorated with dust ruffles and the like.

A low profile box spring serves the same purpose as its high profile counterpart. It provides the same stability and support, as well as bounce, thanks to its combination of numerous coils within the frame.

There are several benefits in using a lower box spring including:

  • Easier getting on and off the bed, especially with a thick mattress on top. This is suitable for people with mobility issues or physical limitations, as is the case for arthritis.
  • Less crowded appearance for the bedroom, particularly when it has a smaller space or a lower ceiling
  • Easier stripping and replacing of the sheets and pillows due to the bed’s lower height
  • Better showing off the decorative headboard

In the end, the choice between a standard and a low profile (bye the way, some people call “low profile spring box” also) will boil down to your personal preference. But if the abovementioned benefits appeal to you, then you should consider going low, so to speak.

Easy Ways to Select the Best Box Spring

With dozens of options in the market, you will likely find it a challenge to choose the best box spring for your unique needs. You will find it easier, fortunately, when you keep these tips in mind.

Make your choice between wood and steel materials

Example of Steel Box SpringBoth materials are strong and sturdy so these will last for several years with proper use and care. But if you want a more portable box spring, your best choice may be steel.

Measure your mattress

The box spring and mattress should obviously fit well. Be sure to measure your mattress at home so that accurate comparisons can be made with the box spring at the store. You may also use the standard sizes used by manufacturers in determining which box spring matches with which mattress.

Check the distance between the wood slats

These are the wooden parts laid out across the top of the box spring, which actually supports the mattress. If necessary, you should measure them so that you are satisfied that their distances are satisfactory. In general, the shorter the distance, the greater the support.

Ask about the warranty

WarrantyThe longer and wider the coverage of the warranty, the better your rights as a consumer can be protected. But don’t rely too much on it as experts suggest changing your box spring and/or mattress every eight years or less depending on its wear and tear.

You should also consider the ease of assembly of the box spring. You have to remember, too, that you will get what you pay for so if you can afford it, it’s best to invest in a high-quality, if relatively expensive, box spring.


The best low profile box spring is the one that addresses your needs in terms of price, comfort, and support, and durable materials and construction. You should then determine how much you can spend, what you are looking for, and what you are willing to compromise on in regards to a box spring for your mattress.

You may also want to think about replacing your mattress. Even the best box spring, whatever its height may be, will not resolve the issues related to a sagging mattress, among others.

Some product Image source:


  • id="comment-340" class="pingback even thread-even depth-1">
    Pingback: Do I Need A Boxspring If I Have Slats? - Mattresses Guide - Mattresses Guide
  • id="comment-442" class="pingback odd alt thread-odd thread-alt depth-1">
    Pingback: What Comes In A Mattress Set? - Mattresses Guide
  • id="comment-443" class="pingback even thread-even depth-1">
    Pingback: Box Spring Alternative Ideas - Mattresses Guide
  • Sohel
    at 2:14 pm

    Very good article on the low profile box spring. I think you should make some changes in your article to make it more readable to your visitors, like- in the review section, change the numbering from 10-1 to 1-10.

    Also, I have seen that you have to give an idea about the low profile box spring or thin box spring but I could not see any information on what is box spring and why we need that? Many people still don’t have the idea about that product and therefore they do not get the proper warranty of their mattress.

    All the best 🙂

  • Adam Bown
    at 9:40 pm

    Hi, thanks for your comment. We have updated the number in the review section. I hope we will add content on the box spring in the future.

  • Molly
    at 6:57 pm

    This is helpful, thank you. We are trying to accommodate 2 arthritic dogs. From the floor to the top of the boxspring is 30″. A 1-yr-old high quality mattress tops the box spring. So we’re not interested in replacing the mattress if we can help it. The boxspring itself is 9 – 10″. The bed frame is 5.5″ from the floor. King size bed. It appears to me that a 5″ low profile box spring will not reduce the height as much as I’d like.

    We found a 2.5″ Beautyrest box spring. Any thoughts?

    Thank you.

  • Jim
    at 6:25 am

    Would be helpful if you distinguished between a foundation (wood/metal platform) and a true box spring (wood/metal layer with wire springs). Are any of these actual box springs or are they all foundations? Do you recommend one or the other for different mattress types?

  • Leave a Reply

    Your email address will not be published. Required fields are marked *