Adjustment Specifications: A. Seat Height: Pneumatic height adjustment capable of a minimum range of 16.5" to 21.5" high B. Seat Depth: A minimum range of 18" to 20" deep C. Arm Height and Width: A minimum range of 1.25 wide and 2.5 high. D. Back Height: Back rest size should be a minimum of 17" wide x 15" high, and adjust a minimum of 3. E. Base: Minimum 5-legged reinforced base. F. Casters: Heavy duty dual-hooded wheel casters with metal stems.