Sleep Philosophy 4 in. Memory Foam Topper upgrades your mattress with a dual-layer design: 2 in. of 2.5 lb. density temperature-control memory foam (with cooling gel for optimal temp regulation) and a 2 in. high-density memory foam base for extra support. It adjusts to your body temp, eases pressure points, relaxes muscles, and offers soft, soothing sleep at a great value. Naturally antimicrobial, hypoallergenic, dust-mite resistant, and Oeko-Tex Certified (no harmful chemicals), it includes a zippered, removable cover-featuring 3M Scotchgard for moisture management and stain release, plus a non-skid reverse side to keep the topper in place. The cover is machine washable (foam needs spot cleaning).Slightly oversized for full-mattress end-to-end coverage, it's efficiently compressed into one box for easy shipping. Unbox, unroll, and it expands to its original shape within 72 hours. Material: Polyester.