Flash Furniture Mid-Back Grey Mesh Swivel Task Chair with Arms Contemporary Task Chair Mid-Back Design. Back Size: 20.5 W Inch x 20.25 H Inch Flexible Gray Mesh Back Material Adjustable Height Lumbar Support Tilt Lock Mechanism. Seat Height: 18.5 - 22.5 H Inch Tilt Tension Adjustment Knob Padded Gray Mesh Upholstered Seat with Black Insert Swivel Seat Pneumatic Seat Height Adjustment Nylon Arms