Push-button assembly for arm and back. Durable, blow-molded, plastic bench. Wide base, and suction-cup tips on two legs in tub offer extra stability and safety. Direction of seat back can be reversed easily without tools. Anodized, aluminum frame adjusts in 1-1/2" increments. for a seat height of 16-1/2" to 21-1/2" above the floor. Fits tubs 11" to 21-1/4" deep. 1" space in seat for shower curtain, Composite. (Single)