Task chair offers a sculpted, molded back with integral lumbar support. Waterfall seat front provides comfortable under-thigh support. Functions include pneumatic seat-height adjustment from 15-1/8" to 20-3/16", adjustable back height, seat-depth adjustment and 360-degree swivel. Five-star base includes 2" hooded dual-wheel casters. Seat size is 20" wide x 18" deep. Usable seat depth is 16-3/8" to 18-1/8". Back measures 16-1/2" wide x 16-3/4" high. Arms for chair are sold separately. Chair is certified by SCS to be in compliance with specific, indoor, air-quality emission requirements. Meets or exceeds applicable ANSI/BIFMA standards.