Ergonomic Laboratory Chair with Black Composite Base Standard Height 23" to 33" Base Diameter 24" Seat Dimension 20"W x 18"D Overall Height with Backrest 38" to 48" Foot Ring Diameter 20" Back Dimension 16"W x 16"H Lateral Back Rest Adjustment Pneumatic Height Adjustment COM Requirements 1 yd Weight Capacity 300 lbs 811 Options 7" Stroke Cylinder: 20" - 27" (Order Ex. 811-7) T Arms (Order Ex. 811-T) Soft Wheel Casters or Glides (Please Specify)