SLEEP100 Firm King Memory Foam Mattress, 12-Inch Gel Cooling Bed in a Box –Adaptive Body Support for Back Pain Relief –CertiPUR-US Certified, No Fiberglass, Motion Isolation, 365-Night Trial, 76x80
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Availability:
In Stock.
Arrives
Tuesday, Apr 28
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Color: White & Black
Size: King
Set name: 12" Luxe Support
Features
- FIRM 3-LAYER ORTHOPEDIC DESIGN: This 12-inch king memory foam mattress features a sophisticated triple-layer structure engineered for those who prefer a firm, supportive surface. The specialized foam layers work in harmony to provide maximum spinal alignment, effectively dispersing pressure points. Combined with a high-density reinforced base, it delivers the consistent firm support necessary to reduce sagging and provide targeted relief for chronic back and joint pain.
- ENGINEERED FOR A COOLER SLEEP CLIMATE: This mattress pairs a high-quality skin-friendly knitted cover with advanced gel-infused memory foam. This specially designed structure enhances airflow throughout the entire multi-layer system, actively dissipating heat to prevent the "sleeping hot" issue. It ensures a fresh, breathable environment, making it the perfect upgrade for any master bedroom or primary suite.
- RELIABLE PERFORMANCE IN EVERY SEASON: Designed for long-lasting durability, our temperature-resilient foam maintains a consistent firm feel regardless of the room temperature. The adaptive surface provides stable support that caters perfectly to back and stomach sleepers who require enhanced structural integrity and a more balanced, level sleeping surface without excessive sinking.
- NON-TOXIC & CERTIPUR-US CERTIFIED: Your health is our priority. This fiberglass-free mattress is crafted with CertiPUR-US certified foams and OEKO-TEX Standard 100 tested fabrics, ensuring it is made without harmful substances or heavy metals. These carefully selected, non-toxic materials support a cleaner sleep environment and reflect our commitment to safe, responsible manufacturing.
- RISK-FREE TRIAL & SIMPLE EXPANSION: Shop with total confidence thanks to our 365-night home trial and 10-year limited warranty. Arriving compressed in a box for convenient setup, this mattress works with most bed frames, including platform beds and adjustable bases. Please allow 2-12 hours for your mattress to fully expand to its original shape and enjoy your first night of premium sleep.
Brand: SLEEP100
Size: King
Product Dimensions: 80"L x 76"W x 12"Th
Item Weight: 71.54 Pounds
Item Firmness Description: Firm
Top Style: Tight Top
Cover Material: Polyester
Number of Layers: 3.0
Fill Material: Gel Memory Foam, High Density Foam, Memory Foam
Weight Limit: 1500 Pounds
Item Firmness Description: Firm
Number of Layers: 3.0
Weight Capacity Maximum: 1500 Pounds
Additional Features: Breathable, Durable, Low Motion Transfer, Pressure Relief, Removable Cover
Construction Type: Memory Foam
Is Customizable?: No
Size: King
Item Dimensions L x W x Thickness: 80"L x 76"W x 12"Th
Item Weight: 71.54 Pounds
Item Dimensions: 80 x 76 x 12 inches
Cover Material: Polyester
Fill Material: Gel Memory Foam, High Density Foam, Memory Foam
Product Care Instructions: Hand Wash Only
Mattress Comfort Layer Material: Memory foam
Material Type: Gel Foam, Memory Foam, Polyester
Brand Name: SLEEP100
Age Range Description: Adult
Model Name: ADULT MATTRESS
Product Benefits: Back Pain Relief, Hypoallergenic, Improves Sleep, Pressure Relief, Stress Relief
Model Number: F2503484
Manufacturer: SLEEP100
Item Type Name: bed_mattress_conventional
Included Components: Mattress, Opening Tool
top-style: Tight Top
Color: White & Black
Style Name: 12 Inch
Shape: Rectangular
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Apr 28
Yes, absolutely! You may return this product for a full refund within 90 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Color: White & Black
Size: Queen
Set name: 14" Luxe Support
Comfortable and a good value.
Reviewed in the United States on April 6, 2026 by Stephen C. Juan
Color: White & Black
Size: Queen
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Un delicioso descanso, firmeza media pero permite relajarse
Reviewed in the United States on April 2, 2026 by david mata
This style of 10-inch gel memory foam mattress is a solid choice if you prefer a firmer feel. It provides good support for your back and spine, which is especially helpful if you deal with back pain or sleep on your back or stomach. The firmness keeps you from sinking too much, while still giving some cushioning from the memory foam. The gel-infused foam helps with temperature control, so it doesn’t trap as much heat as traditional memory foam. That makes it more comfortable for all-night use, especially if you tend to sleep warm. Gel memory foam is commonly used to improve cooling and reduce heat buildup while still contouring to the body . Motion isolation is another strong point—movement doesn’t transfer much, so it works well if you’re a light sleeper. The main downside is that firm mattresses like this can feel a bit stiff at first, especially for side sleepers who need more pressure relief on shoulders and hips. Overall: A great option if you want a firm, supportive mattress with decent cooling and minimal motion transfer, especially for back or stomach sleepers.
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Reviewed in the United States on April 12, 2026 by Big Al
I’ve been using this 10-inch gel memory foam twin mattress for a few weeks now, and I’m really impressed. It has a true firm feel without being uncomfortable, which has made a noticeable difference for my back support. I used to wake up with stiffness, and that’s pretty much gone now. The gel cooling feature actually works—no overheating during the night, which is a huge plus if you tend to sleep warm. It contours nicely to your body while still keeping you supported, so you don’t feel like you’re sinking in too much. Setup was super easy—just unbox, unroll, and let it expand. It fully took shape within a day. Another thing I really appreciate is that it’s CertiPUR-US certified and fiberglass-free, which gave me extra peace of mind. Motion isolation is also solid. If someone moves on the bed, you barely feel it, making it great for light sleepers. Overall, this mattress is a fantastic value for the price—comfortable, supportive, and well-made. Highly recommend if you’re looking for a firm mattress that helps with back pain!
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Reviewed in the United States on April 6, 2026 by Mrs. D
I’ve used this mattress a few times, and it offers a decent, middle-of-the-road experience. The medium-firm feel is pretty accurate—it’s not overly soft or too hard, and it does a reasonable job of contouring to your body without feeling like you’re sinking too much. It seems to follow the typical memory foam feel that a lot of people expect, especially for a twin setup, and it worked fine whether lying on my back or side. That said, it doesn’t really stand out compared to other memory foam mattresses. While it’s advertised as having a multi-layer system for pressure relief and support, the overall feel is fairly standard. It’s comfortable enough for everyday use, but I wouldn’t say it noticeably improves sleep quality or offers anything unique beyond what you’d get from similar options. It also seems like it could be prone to wear over time if not taken care of, which is something to keep in mind. One positive is that it didn’t have a strong chemical smell, and the materials feel reasonably well-made. It expanded as expected and fit the frame without issues. Still, after using it a few times, my impression is that it’s a solid but unremarkable mattress—good as a basic or backup option, but not something that really sets itself apart despite the claims.
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Reviewed in the United States on March 30, 2026 by Phil C.
The 12-Inch Memory Foam Mattress in a Box is a standout choice for anyone seeking a "custom-fit" sleep experience without the luxury showroom price tag. Its multi-layered memory foam construction provides exceptional contouring support, effectively cradling high-pressure areas like the hips and shoulders while maintaining proper spinal alignment. For those who share a bed, the motion isolation is a game-changer; the viscoelastic foam absorbs movement so efficiently that you’re unlikely to feel a partner (or a pet) tossing and turning throughout the night. What truly elevates this mattress is the commitment to safety and comfort. Being fiberglass-free and non-toxic offers peace of mind for health-conscious shoppers, as it utilizes plant-based fibers or specialized fire barriers instead of irritants. The breathable knit cover works in tandem with the foam's open-cell structure to promote airflow, addressing the common "sleeping hot" issue often associated with traditional foam. With a 365-night trial, it removes the risk of a "blind" purchase, allowing your body the necessary 30-day break-in period to fully adjust. This mattress is a top-tier "all-rounder" that balances pressure relief with long-term durability. It’s an ideal investment for side and back sleepers who want a safe, cool, and undisturbed night's rest backed by an industry-leading trial period.
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Reviewed in the United States on March 25, 2026 by JArencibia
Really good mattress. I got it to replace one in extra bedroom. It's s amazing how it starts to expand as soon as the vacuum seal is broken. Almost explodes out of the packing. It doesn't take more than a few minutes before it's almost to its full height. It was ready to sleep on that same night. It's so comfortable. I love the memory foam mattresses. So much more comfortable than the older style mattresses. Thanks to the vacuum seal process you can know get a very comfortable mattress at a affordable price and have it shipped to you, carry it in the house and install it yourself. If you in need a comfortable mattress on a tight budget, order one of these. You won't be disappointed. Really great for kids bedroom or a guest room. The young couple sleeping on this one absolutely love it. It had expanded to full height in just a few hours. With the black around the bottom they look nice too.
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Reviewed in the United States on March 28, 2026 by Sharon Dixon