The Keynote Memory Foam collection by Serta Mattress features a 2nd Generation high-density 4 lb Kool-Comfort memory foam surface that is great for pressure relief and continual support and helps regulate heat better than standard memory foams. The Keynote helps to distribute pressure evenly across the entire body, providing perfect alignment and firm support. Also, a deluxe patented "Hi-Density" 23 ILD support foam ensures that body impression and sags will be prevented throughout the mattress's 10 year full coverage non-prorated warranty.Buy only the best from Bradley's Sleep, now at hundreds of dollars less!