Better shut eye at an eye-opening price? The Casper© Slate has 3 layers of premium foam, with a breathable, cradling feel that responds to pressure points and soothes you into a comforting night's sleep. Key features: a cozy knit cover designed with added stretch so you can experience all the comfort your mattress has to offer. Features a top layer of breathable flex foam that's both responsive and breathable to soothe you to sleep with the perfect bit of bounce. A firm Casper core base provides long-lasting support while preventing sinking and sagging. Mattress arrives compressed in a box and then regains its size and shape after opening.