● Quadragel pack has four compartments designed to prevent gel migration. It helps skin and retains body temperature to provide maximum comfort. Non-skid flat bottom. Single-layer foam construction contours to users body, reducing high pressure areas. Comes in 2" and 3" thickness. ● Covers- STRETCH-AIR FABRIC — designed for air transmission and heat reduction. This two-ply, breathable laminate combines a highstretch polyester top layer with a waterproof, breathable vapor barrier. COMFORT-TEK — fluid proof exterior has supple leathery properties that provide an easily cleaned surface and protection for the inner cushion. Comfort-Tek has multidimensional stretch and helps alleviate pressure on bony prominences.