FATHOM Medium King Mattress 12 Inch Memory Foam Mattress King Size Bed in a Box for Back Pain Relief and Cool Sleep with Gel Foam and Removeable Fiberglass Free Cover, CertiPUR-US Certified
Condition: New
Buy Now, Pay Later
As low as
$48.06
/ mo
Learn more
- – 6-month term
- – No impact on credit
- – Instant approval decision
- – Secure and straightforward checkout
Ready to go? Add this product to your cart and select a plan during checkout.
Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Apple Pay, and PayTomorrow. No-credit-needed leasing options through Acima may also be available at checkout.
Learn more about financing & leasing here.
Selected Option
Free shipping on this product
100-day returns
Learn more
100-day refund / replacement
To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
Availability:
Only 4 left in stock, order soon!
Arrives
Saturday, Dec 27
Recently Viewed
Size: King (U.S. Standard)
Style: 12 Inch
Pattern Name: Medium
Features
- Advanced Cooling Comfort: The AeroFusion gel memory foam mattress ensures exceptional breathability and heat dissipation, adapting precisely to your bodys contours while resisting temperature sensitivity. Enjoy cool, cradling comfort no matter the season.
- Premium, Thoughtful Design: Wrapped in a soft, geometric-patterned jacquard fabric with stylish light gray graphene yarn borders. The fiberglass-free mattress cover is not only elegant but functional, featuring a zipper for easy removal and cleaning.
- Motion Isolation Technology: Dynamic memory foam mattress contours to your bodys unique curves, filling gaps to support optimal spinal alignment while effectively lowering motion transfer and noise, ensuring a serene and undisturbed sleep environment where everyone wakes up refreshed, ideal for couples and kids.
- Certified Safe Material: Crafted in the USA with CertiPUR-US foams and globally sourced Oeko-Tex certified fabrics, our king mattress is free from harmful substances. Backed with a 10-year protection, Fathom mattress is designed to promote spinal health and long-term durability for a healthy lifestyle.
- Effortless Setup: The Fathom mattress in a box is vacuum-packed, compressed and rolled for easy movement and installation. Simply open and unroll your memory foam mattress, then enjoy it within 72 hours for full expansion.
Brand: FATHOM
Size: King (U.S. Standard)
Product Dimensions: 80"L x 76"W x 12"Th
Top Style: Gel Top
Cover Material: Polyester
Number of Layers: 4.0
Fill Material: Gel Memory Foam, Memory Foam
Special Feature: Breathable, Durable, Low Motion Transfer, Pressure Relief, Temperature Regulating
Color: Medium
Model Name: Fathom Medium 12" K
Product Dimensions: 80 x 76 x 12 inches
Item Weight: 80.8 pounds
Manufacturer: FATHOM
Item model number: Medium 12 K
Date First Available: April 23, 2025
Age Range Description: Adult
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Saturday, Dec 27
Yes, absolutely! You may return this product for a full refund within 100 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.
- Klarna Financing
- Affirm Pay in 4
- Affirm Financing
- Afterpay Financing
- PayTomorrow Financing
- Financing through Apple Pay
Learn more about financing & leasing here.
Similar Products
Top Amazon Reviews
Size: Queen (U.S. Standard)
Style: 10 Inch
Pattern Name: Medium
I bought the FATHOM Medium Queen Mattress (10-inch, memory foam) a week ago and started using it right away. So far, I am very pleased with the overall quality, comfort, and thoughtful design of this mattress. The cooling comfort is noticeable from the first night. The AeroFusion gel memory foam does an excellent job of dissipating heat and adapting to my body. Unlike some mattresses that trap warmth, this one keeps me cool throughout the night, making sleep more refreshing and uninterrupted. I also appreciate the medium firmness level. It feels supportive without being too hard, providing a balanced surface that relieves pressure points while maintaining good spinal alignment. After a week of use, I can already feel a difference in back comfort, and I wake up less stiff than I did with my old mattress. The motion isolation technology is another standout feature. The memory foam absorbs movement effectively, so even when my partner shifts during the night, I hardly notice it. This has really improved our overall sleep quality since disturbances are minimal. Design-wise, the mattress cover is both practical and stylish. The geometric jacquard fabric looks modern, and the light gray graphene yarn borders add a touch of elegance. The cover is also fiberglass-free and removable, making it safe and easy to clean—something I find very convenient. I also appreciate the peace of mind that comes with certified safe materials. Knowing that the mattress is CertiPUR-US certified and Oeko-Tex certified assures me that I’m sleeping on something free from harmful substances. The 10-year protection is another bonus, showing the brand’s confidence in long-term durability. Setup was quick and hassle-free. The mattress arrived vacuum-packed and rolled in a box. It was easy to move into the bedroom, and after unrolling, it started expanding right away. Within a day, it was ready to sleep on, though full expansion took closer to 72 hours. After a week of use, I can confidently say the FATHOM Medium Queen Mattress offers excellent comfort, cooling, and support. It’s well-made, safe, and thoughtfully designed for a good night’s sleep. So far, it feels like a great investment in both comfort and health.
...
show more
Reviewed in the United States on September 28, 2025 by Yeok
Size: Queen (U.S. Standard)
Style: 12 Inch
Pattern Name: Firm
For the money this was a great deal, but definitely missing some features found in higher quality mattresses. But at the price point they focused on comfort. Some higher quality mattresses have denser perimeters this doesn't so you could roll off easier or sitting on the edge sink in more. For fit, generally you want a firmness to match your weight class. I'm 280lbs 6ft tall, wife is 230lb 5'5" tall, this falls in a nice comfort range for us. I can sleep on my back, side or stomach and it seems to contour nicely keeping my spine straight. If you are much lighter you may want a softer bed. I went with the 12" mattress, I've usually go with 8" Walmart or low end Amazon mattresses and they generally do not hold up. I'm hoping a 12" mattress will last a little bit longer than just a few years. Height seems like a good spot as well
...
show more
Reviewed in the United States on November 15, 2025 by Chris
Size: Twin XL
Style: 12 Inch
Pattern Name: Medium
Skeptical about buying a mattress without trying but the price and features made it reasonable to assume this mattress was good. This mattress turned out to be great! Took about a day for the mattress to fully expand. This mattress is very comfortable. I’m a big guy, over 250 pounds and this mattress is comfortable. I don’t sink in and bottom out. Absolutely no sound from the mattress, no squeak or whooshing noises. I have this paired with the adjustable base, it works perfectly. The memory foam is supportive and cool, I don’t overheat on this mattress. I can get an easy 8-10 hours of sleep with no back pain! Take a chance and give this mattress a try, you won’t regret it. Like the fact that the cover is removable and machine washable.
...
show more
Reviewed in the United States on November 8, 2025 by Amazon Customer
Size: Queen (U.S. Standard)
Style: 10 Inch
Pattern Name: Medium
I recently purchased the FATHOM Medium Queen Mattress (10-Inch Memory Foam), and I couldn’t be happier! The mattress arrived neatly packed in a box and was super easy to unbox and set up — it expanded fully within just a few hours. The medium firmness is perfect — soft enough to contour to my body but firm enough to provide excellent support for my back. I’ve noticed a huge improvement in my sleep quality; I wake up refreshed and without any stiffness or soreness. The memory foam feels premium, and it keeps me cool throughout the night, which is a big plus. For the price, this mattress is an absolute steal. If you’re looking for a comfortable, supportive, and high-quality queen mattress, I highly recommend the FATHOM Medium 10-Inch Memory Foam Mattress. You won’t regret it!
...
show more
Reviewed in the United States on November 7, 2025 by Rakhi
Size: Queen (U.S. Standard)
Style: 10 Inch
Pattern Name: Medium
I got this mattress for my 74 year old dad because his old bed had started to get a big dip in the middle. After opening, we let it expand for about 24 hours, just to make sure it was fluffed up. He went to lay on it this afternoon and was asleep in less than 5 minutes. He didn't get up or toss and turn, like he did in the old bed. It turned into a 6 hour nap, and when he woke up, he said he had way less pain and stiffness with this new mattress. I'm hopeful that over time, he will feel better overall since his sleep will be better. I laid down on it myself. It's very comfortable and doesn't feel cheap. The price can't be beat, so that was another bonus.
...
show more
Reviewed in the United States on October 29, 2025 by SnarlSnarlMeowMeow
Size: Twin XL
Style: 10 Inch
Pattern Name: Medium
Everything else is great about the mattress, particularly how it was boxed and covered in sheets of plastic to ensure no foreign matter contaminates it until you cut the protector off. Unfortunately, after 96 hours, it measures 9 inches-not 10. Another reviewer stated this also. I wish I had the extra inch for comfort and height. It's a bit firm for my small body and I'm unable to sink in sufficiently. I recommend going with 12" instead of 10" if you want at least 10 inches.
...
show more
Reviewed in the United States on November 4, 2025 by Amazon Customer