Pneumatic Task Chair adjusts to provide all-day comfort for workers of almost every size or shape. Thick, wide cushions with bolsters offer extra support. Hinged back allows the fully upholstered back to pivot. Functions include pneumatic seat-height adjustment from 16-1/4" to 21-1/4", back-height adjustment and 360-degree swivel. Five-star base has hooded dual-wheel casters. Arms (height and width adjustable) to chair are sold separately. Usable seat depth ranges from 15-3/4" to 18". Seat size is 20-1/2" wide x 18-1/4" deep. Back measures 17-1/2" wide x 16" high. Chair is available in black frame only and meets or exceeds applicable ANSI/BIFMA standards.