Spring Air is an American mattress manufacturer that has been producing high quality sleep products for over 50 years. They're known in the industry for having luxury models at less-than-luxury prices. The Isabel Firm is a brand new model. 

The Isabel has a 700-Count (Queen) individually-wrapped pocket coil back supporter spring unit that is foam encased with a noticeably dense wall of foam.

The feel level of this mattress falls into the luxury firm category; it's going to provide lots of support - even to the largest individuals - but it will have enough 'give' for those who sleep on their sides and need a bed to conform to their natural curvature. 

Hover or touch to zoom in
Other Views:

Isabel Firm - A BackSupporter Mattress

$999 for 28 x 42 mattress
free shipping
Optional Boxsprings:

Other Custom Accessories

All sheet sets are hand-made of luxurious material and include the fitted sheet, flat sheet and 1-2 pillowcases. They come in a variety of solid colors, most of which are pictured here. We will call you after your order is placed to discuss what colors are available for you at this time.

*We will call you to select your sheets color before shipping.
free shipping

Mattress Scale

Approx. Height of Mattress: 11"

This Mattress Features:
pocket coil mattress Individual Pocket Coil Springs offer much better motion isolation than traditional springs and will also better flex to your body shape.

CertiPUR-US certified foams are:

CertiPur-US ✓ Made without ozone depleters
✓ Made without PBDEs, TDCPP or TCEP (”Tris”) flame retardants
✓ Made without mercury, lead, and other heavy metals
✓ Made without formaldehyde
✓ Low VOC (Volatile Organic Compound) emissions for indoor air quality (less than 0.5 parts per million)
✓ Made without phthalates regulated by the Consumer Product Safety Commission


Phase Change Technology - continually adjusts to temperature to Breathable Tight Top Cover 

Mattress(Top Side)
Back Supporter Comfort Bridge Design - acts as a stabilizer layer inside the mattress to enhance support and reduce motion transfer across the sleeping surface.

BackSupporter Spring Unit - this dual-gauge zoned design features firmer coils in the center for added support in the lumbar area.


10 Total Years (10 full)

Expert Review:
Isabel Firm - A BackSupporter Mattress

The Spring Air Isabel Firm mattress is a high-quality sleep solution for those looking for a supportive and comfortable sleeping surface. With over 50 years of experience in the industry, Spring Air has a reputation for producing luxurious sleep products at an affordable price. The Isabel Firm is a brand new model that combines the best of both worlds - the support of a firm mattress and the comfort of a luxury bed.

At the heart of the Isabel Firm is a 700-count individually-wrapped pocket coil back supporter spring unit. This unit provides the mattress with a strong and supportive foundation, making it an excellent choice for individuals of all sizes. Additionally, the coils are foam encased, which helps to reduce motion transfer and ensure a comfortable sleep experience.

The feel of the Isabel Firm is luxurious firm, making it an excellent choice for those who need a supportive bed but still want to maintain a comfortable sleep surface. The dense foam encasement helps to conform to your body, providing pressure relief to your joints and muscles. This makes it a great choice for those who sleep on their sides, as it helps to reduce the pressure on your hips and shoulders.

In summary, the Spring Air Isabel Firm mattress is a high-quality sleep solution that provides the support and comfort of a luxury mattress at an affordable price. With a 700-count pocket coil unit, dense foam encasement, and luxurious firm feel, this mattress is an excellent choice for anyone looking for a supportive and comfortable bed.


Other models you may like:

View More >>


  • Free shipping or delivery of this item to the 48 contiguous states only. Delivery of this item to Alaska, Hawaii, US Territories or APO/FPO addresses will require added charges. Please call customer service for rates and availability.
  • Some mattresses and accessories will ship via FedEx or USPS, otheres will use a freight service.
  • Free LTL freight delivery to most areas in the continental US. Destination must be accessible by large truck. Some locations may have a small surcharge.
  • Delivery service is to your driveway or parking lot only. White Glove is available for an extra fee.
  • If you have any special deadlines or delivery requirements, please give us a call to review options.
  • For complete details, read our Shipping Policies.


Measure all 4 sides of your mattress and bed frame before ordering.
We recommend you order the mattress 1 inch smaller than the space it is meant to fill. This will leave extra room for sheets, blankets, and variations in production size. Some people like a larger gap to really have room for your hands to reach down and change sheets easily. Please note that production size is not guaranteed to be exact.

Common Questions About Ordering Custom Size Mattresses

What if it doesn't fit?
We will never ship out a custom mattress or boxspring that exceeds the size you have ordered without contacting you first to check if the size variance will cause an issue. Since these are custom made for you, they can not be returned, so please be careful when taking measurements. On some bed sets, the box spring will be a different size than the mattress so you will need to measure both pieces. Also, since beds are often set up not perfectly square, you will need to measure all four sides of the bed to find the correct size. Be sure to check in the corners for boards or bolts that often protrude in to the mattress area, and order your custom mattress and custom boxspring small enough to fit inside of these protrusions.
What sizes are available?
Any custom size is available upon request but with most models you are limited to being smaller than a King mattress. If you need a custom size bigger than a King, here are some models that can be supersized. If you don't see your size listed, please call us to find out what prices would be.
Can I really order any size and shape?
Yes, we are able to make some of our models in odd shapes (like cut or rounded corners) for antique beds, RVs, and even boats; however most of them can only be done in a 4-sided rectangle. Here is a model that can be made in any shape. You can call us to order by phone, or just select your approximate size, place the order online, and we will definitely give you a call back to discuss you exact shape before we start building anything.
We recommend you order your custom mattress 1-2 inches smaller than the space it is meant to fill. This will provide extra room for tucking in sheets and blankets.
Our online shopping lets you select a model to the nearest inch but most of the time we can even do half-inch increments for a perfect fit. We call ALL of our online buyers before we start building anything. This allows us to discuss your exact size and make changes before production begins. This lets you buy online now without fear of getting the wrong size.
What about the boxspring ?
It is very important to measure the size of your box separate from your mattress because in many older bed sets, the box was made slightly smaller than the mattress. The length and width of a solid foundation boxspring can be custom made to fit exact dimensions. The thickness can not be customized but boxes are available in several standard thicknesses ranging from 2-9 inches.
How soon will my custom size mattress arrive?
Once your order is paid for, a specialist from Michigan Discount Mattress will call you on the phone to verify your sizes and delivery information. Production will then begin and usually takes 1-3 weeks. After production, the custom mattress will be packaged at the warehouse to protect it during shipping to your home. Shipping takes 2-10 days depending on the destination city. The combination of producing, packing, and delivering means that you should receive your custom mattress within 2-6 weeks of the day you order. If you need a more accurate estimate, or have a quicker deadline, please give us a call to discuss expediting options.

Facebook YouTube Blog Mattress Information and Sales Twitter

Michigan Discount Mattress

10 Year Warranty