Orthopedic Wedge Pillow Seat Cushions help promote proper sitting posture to reduce painful pressure on the lower back buttocks and tailbone. Combine with Accubead cushion or heated seat cushion for more comfort in office chairs or vehicles. Soft but firm comfort. Durable foam pillow has zippered washable navy velour cover. Cut out section to relieve painful pressure on tailbone. Dimensions: 16 Inches Long by 12 Deep (At Center). Tailbone Cut-Out is about 6 inches by 5 by 6. Thickness of wedge pillow: About 1.5 at cushion front and 2.5 at back.