Solid Seat Back * 18 W X 16 D X 1 1/2 * Custom And Bariatric Sizes Are Available * Used To Properly Align The Body As Well As To Eliminate The Sagging Effect Found In Standard Sling Seat Wheelchair Upholstery * Safety Straps Secure The Solid Back To The Wheelchair * Cushion Uses Medium Density Foam And Is Covered Using Waterproof Black Leatherette Cover