Mellow's 4-inch 5-zone topper with cooling gel infusion is a premium memory foam mattress topper made with CertiPUR-US certified foam that instantly revamps your old mattress for maximum comfort and better sleep. Our topper features 5 body zones with different points of contact all throughout the body to prevent tossing and turning. Its breathable body-conforming memory foam is infused with gel to help reduce trapped body heat, keeping you cool and your mattress fresh. Responsive active suspension isolates motion to provide undisturbed sleep for you and your partner.