Boss Office Products B580 Boss Web Chair in Black The Boss Web Chair is upholstered with a unique "Web" mesh material which allows air to pass through The "Web" back distributes weight evenly, and provides the perfect level of back support The patented "Web Tension Knob" allows the user to tighten or loosen the tension of the mesh material with a few simple twists This is a unique feature you will find only on the Boss Web Chair, The seat surface and the outer back areas are upholstered with genuine LeatherPlus Pneumatic gas lift seat height adjustment; Adjustable tilt tension control Unique office chair with mesh web back and patented web tension control knob Seat upholstered in genuine black leather; armrests are molded polyurethane Pneumatic seat height adjustment; adjustable tilt tension control Weight capacity is 250 pounds; easy assembly upon arrival Measures 27-1/2 inches wide by 27 inches deep; adjusts between 41-1/2 45 inches high