This Web Chair is upholstered with a unique “Web” mesh material which allows air to pass through, adding to long-term comfort by preventing body heat and moisture build up. The “Web” back distributes weight evenly, and provides the perfect level of back support by conforming to each individual’s back shape. As with any fabric material, the “web” mesh will stretch and loosen the tension over extended periods of usage. That’s why we’ve invented the patented “Web Tension Knob”located underneath the seat to strengthen the tension of aging mesh material with a few turns. 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. Large 27” nylon base for greater stability. Hooded double wheel casters. Adjustable heights armrests. Weight Capacity: 250lbs.