A quality design at an affordable price, these chairs are ideal for home, office, study, or shop. Features include pneumatic height control, polypropylene seat and back shells, a height- and depth-adjustable hinged backrest, dual-wheel casters, and a 24" diameter reinforced nylon base. Seat cushion is 18"w x 17"d x 2" thick. Backrest is 14"w x 12"h. Includes CK49 height extension kit and adjusts from 24½" to 29½". Black.