SeatFlex Chairs are made of a series of elastic bands that conform to your body for the ultimate sitting experience. The Seatflex seat is on the higher end of standard seat heights in order to compensate for the deflection of the support cords. Chairs feature a light weight plastic base and pneumatic height adjustment. Seat adjusts from 16.5" to 20" in height. Tilt, rock, and height adjust easily with one hand. Rock and recline can lock into position for added stability.