16"D. 16"D. Adjustable air pressure provides relief based on individual needs. Includes easy-to-use air pump. Low surface tension reduces friction and skin shear. Includes low-shear fluid-proof cloth cover (not shown) protects against incontinence. Straps to wheelchair. holds cushion securely in place. Adjustable air pressure provides relief based on individual needs. Includes easy-to-use air pump. Low surface tension reduces High-density foam with durable Sure-Chek vinyl cover. Anti-bacterial incontinence-resistant cover is removable. Rear buckle strap