Inside the One: Our signature all foam mattress designed with a responsive yet supportive medium-firm feel is perfect for any sleep style. Best Solution For: Back and stomach sleepers. Features a top layer of Breathe Flex Foam that's both responsive and breathable to soothe you to sleep with the perfect bit of bounce. Feel deep pressure relief with Align Memory Foam that cradles your body to help you stay asleep. A firm Casper Core base provides long-lasting support while preventing sinking and sagging. A breathable comfort layer allows for airflow for more comfortable sleep.