The Simmons 700 Series Wrapped Coil Technology provides exceptional pressure relief and conforming back support * High performance; durable foam layers * Knit fabrics provide soothing; soft feel for more comfortable sleep * No Flip Design means this durable mattress never needs to be flipped or rotated * Coil Density: Twin-512; Twin XL-546; Full-693; Queen-836; King- 1064; Cal King - 1061