Big Man’s Double AirGrid® Back and Layered Leather Seat Ergonomic Chair with Built-in Adjustable Lumbar Support. Thick Padded Layered Leather Seat and Double AirGrid® Back with Built-in Adjustable Lumbar Support. One Touch Pneumatic Seat Height Adjustment. Mid Pivot Knee Tilt Control. Adjustable Tilt Tension Control. Height and Width Adjustable Arms with PU Pads. Big and Tall to 400lbs. Extra Heavy Duty Gunmetal Finish Base with Oversized Dual Wheel Carpet Casters.