The comfort of a Hybrid, the Stearns & Foster way. A stretch-knit covering features Tencel, which is a sustainably sourced fiber used in athletic wear that is designed to wick away moisture and keep you comfortable. The Intellicoil is a nested coil design that provides even more adaptive support for every type of sleeper. This mattress also features the airvent system that works with external air vents to increase breathability and promote cool, comfortable, deep slumber throughout the night. Two Twin XL low profile foundations complete this set.