McCarty's Sacro-Ease Ergo Wedge Seat Support Cushion Wedge shaped to level out your seat bringing your hips and knees to a neutral position, reducing the impact to the spinal discs Made with Poly foam and comfort memory foam for maximum comfort. Removable insert in the tailbone area Durable non skid bottom. Size is 15' x 16' x 3' and slopes down to 1" in the front