This unique gel memory foam mattress topper senses where your body needs the most support and provides personalized comfort with microgel beads. breathable, open-cell design provides allover ventilation to prevent heat and moisture accumulationkeeping the material cool, fresh and hygienic removable 210 thread-count polyester cover 2 thick memory foam is infused with microgel beads for luxurious cradling comfort easily secures to mattress with a fitted sheet or mattress cover, sold separately 100% visco-elastic memory foam Washable polyester cover; spot clean foam. Made in America. Twin mattress topper: 74x38x2H Twin XL mattress topper: 79x38x2H Full mattress topper: 74x53x2H Queen mattress topper: 79x59x2H King mattress topper: 79x75x2H Cal. King mattress topper: 83x71x2H Memory Foam Tips: remove from packaging within 72 hours after unwrapping, air product for a few hours to eliminate trapped odors allow 48 hours for this product to return to its original shape Topper dimensions may be sized slightly smaller than your mattress for a secure fit under your sheets.