Master Caster 91061 Deluxe Seat/Back Cushion w/Memory Foam, 17w x 2 3/4d x 17 1/2h, Black Reduces back strain and helps eliminate fatigue caused by improper seating posture. Unique, patented system of interchangeable foam inserts can be arranged to fit any body size or shape. Memory foam conforms to the body's natural curves. The forward tilt of the seat cushion relieves stress from the lower spine and pelvic area. When used as a back cushion provides proper seat depth dimension. Hook and loop strap holds cushions in place on fabric seating, adjustable strap for smooth seating. Flame retardant, washable cover. Made in the USA.