The Hanover 8-In. Tranquility Memory Foam King Mattress is made of a 2-In. solid memory foam and a foam base composed of a high density foam that provides long-lasting durability and support. The entire mattress is protected with a bridal white elegant knit removable washable cover and a 20-year warranty. All Hanover mattresses are CertiPur certified which means they are made without ozone depleters PBDE flame retardants mercury lead other heavy metals formaldehyde or phthalates.