The Action Akton Professional Cushion with Basic Cover is a made of 100% Akton viscoelastic polymer which provides exceptional pressure relief. Wheelchair users at risk of skin breakdown or with a history of pressure ulcers will find this 1-5/8 inch thick pad provides effective weight distribution. The Professional Cushion provides additional cushioning against pressure, shear, and vibration. Active clients using a power wheelchair who are concerned about the potential effective of increased temperatures due to foam insulation, or bottoming out will find this cushion effective and comfortable. The Professional Cushion is helpful for people using wheelchairs, power wheelchairs, scooters or for other situations that require prolonged sitting. The Basic Cover included is made of a durable stretch knit material which is essential for utilization of the protective cushion properties. The soft black pontae fabric cover has a non skid bottom, zippers on 3 sides, and is easily removable and washable. This is a non-returnable hygiene item. Action Akton Professional Cushion with Basic Cover Specifications: Thickness: 1-5/8 inch. Sizes: 16W x 16D, 16W x 18 D, 18W x 16D, 18W x 18W, 20W x 20D. Material: 100% smooth AKTON polymer. Shipping: UPS Ground.