Sleep Master 12-Inch Pressure Relief Memory Foam Mattress and Platform Metal Bed Frame/Mattress Foundation, King Mattress layers include: 3 memory foam (3 lbs. density), 3 super soft foam with pressure relief system, and 6 high density foam base. Steel bed frame eliminates need for a boxspring The mattress is shipped in a small box and can take up to 48 hours to fully expand from its compressed state. CertiPUR-US Certified Limited 5 year warranty