24-hour task chair offers a different kind of seating experience to meet a vast variety of users. The difference is in the design. Alday 24/7 Task Chair was designed as an extensive-use task chair, rated for 500 lb. and 24/7 use. The ample supportive cushioning in the seat and back deliver ergonomic shaping to fit a variety of body types while providing all-day comfort. Durable, plastic, ergo core back and reinforced mechanism with back tilt add even more comfort and overall strength. Upholstery is made of 100 percent polyester. Functions include pneumatic seat-height adjustment (from 17-1/2" to 20" high), back-height adjustment and 360-degree swivel. 26" diameter five-star base rolls easily on 2-1/2" diameter, dual-wheel carpet casters. Arms are not included. Seat size is 20-1/2" wide x 20" deep. Back measures 18-3/4" wide x 18" high.