Choose from the available size options. Firm gel memory foam and innerspring mattress. 14.75 in. thick hybrid mattress. ActivPur and gel-infused memory foam layers. Pocketed coils and BackCare 3X with microcoils. Optional box spring in choice of available sizes, heights. 10-year manufacturer's warranty. For a deeper, more restful sleep, the Beautyrest Platinum Haven Pines 14.75 in. Luxury Firm Mattress offers the cooling, pressure relief of memory foam combined with the benefits of individually wrapped springs. This luxury firm mattress has layers of antimicrobial and cooling memory foam plus Beautyrest pocketed coil technology and BackCare 3X, which is engineered with 2,000 additional pressure relieving microcoils. It's offered in your choice of available size options. Make this luxury firm hybrid mattress complete by adding the optional box spring foundation, which comes in your choice of available size and height. Size: Twin XL.