Hanoverís Tranquility mattress will allow you to enjoy a cool and comfortable night sleep, thanks to the pressure-sensitive memory foam with open cell technology that allows for a cooler mattress. Each mattress is made of a solid memory foam and a foam base that is composed of VertaFirm high-density foam and provides long-lasting durability and support. The removable, washable mattress cover provides a plush, sleep surface and lasting comfort and durability. The entire mattress is protected with a 20-year limited warranty that reflects premium quality and workmanship. 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.