Frameless back of the Thrill Task Chair provides the flexibility you desire and easily adapts to your unique shape for sensational comfort. The open design of the poly back provides exceptional ease throughout the day. Complete your style with a classic black frame and a black nylon base. This chair offers synchro tilt mechanism with tilt lock and tilt tension to keep you relaxed no matter your preferences. Other functions include 360-degree swivel, pneumatic seat-height adjustment from 15" to 19", tilt lock and tilt. Included arms adjust in height from 27-1/2" to 29-1/2" high. 24" diameter five-star base rolls on 2-1/2" diameter, dual-wheel carpet casters. Chair offers a 250 lb. capacity. Seat size is 19" wide x 19-1/2" deep. Back measures 18" wide x 19-21" high.