McKesson Donut Seat Cushion, 16 in., 1 Case of 6 Stair Chairs Ergonomically designed to provide ideal Cups are 7 Ergonomically designed to provide ideal spinal alignment to help reduce lower back leg hip ankle or joint pain * Sleeping or sitting can be difficult for those with back leg hip or joint pain * A knee pillow when placed between the legs keeps your legs hips and spine parallel and aligned* This results in improved circulation and decreased pressure and strain on those areas * The high quality memory foam reacts fast to provide instant relief and comfort and provides slow memory foam recovery for longer support * The removable soft polyester and rayon cover zips off easily for machine washing * Hypo allergenic * 10 1 2 L x 8 W x 7 3 4 H * Small base design allows for easier maneuverability the molded foam's open center and conforming characteristics minimize pressure point discomfort Designed for excellent comfort and support while seated