This Softseat has an innovative design that allows you to customize the amount of cushion wanted. On the seat is an air release valve that allows you to choose how much cushion you want. Opening the valve will allow the seat to fill with air. Simply sit on the cushion and open the valve until the point of desired cushion.The top of the seat has a suede finish whereas the bottom has an anti slip material. This seat has two straps to attach to the original seat for a universal and secure fit. It also comes with a carrying bag for easy storage when compressed. Approximate Softseat Dimensions (LxWxH):Small - 11" x 10"-7" x 1"Large - 15" x 14" x 1"