Serene Performance Foam is the greatest advancement in comfort technology since memory foam. Serene foam relieves pressure better, sleeps cooler, and recovers faster than memory foam. It reduces motion transfer and provides outstanding support allowing you to sleep deeper, longer, and wake refreshed. This is absolutely the best 'performance sleep gear' available today. Serene Performance Foam typically recovers within 1 hour after removing from packaging. Features:Serene Performance Foam - Fast recovery, typically within 1 hour after removing from packagingComfort Tech, Active Air Technology and Serene are Registered trademarks of Carpenter Co.Made in the USAHeat dissipates quickly for a cooler nights sleepFirmness: MediumMemory Foam Type: FoamDensity: 2.5 PoundType: Mattress TopperProduct Features: HypoallergenicThickness: 3 InchCare Instruction: Spot CleanSupport: MediumSize: Twin, Queen, Full, King Dimensions:Twin: 3 inches high x 38 inches wide x 75 inches longFull: 3 inches high x 54 inches wide x 75 inches longQueen: 3 inches high x 60 inches wide x 80 inches longKing: 3 inches high x 75 inches wide x 80 inches longFoam Tips: Arrives tightly packed in portable box for customer convenience.Remove from packaging within 72 hours to maximize latex foam expansion.You can sleep on it the same night it is unwrapped, however allow 48 hours to fully return to its original shape.Vacuum sealing sometimes traps odors. After unwrapping, air product for a few hours to eliminate trapped odors.Due to machine-cutting manufacturing processes, there may be slight variances in the dimensions of this product.Due to the nature of foam, the firmness level of similar products may produce different firmness results.Once opened this product is non-returnable.