All-purpose chair features a weave mesh back and seat for generous lumbar and pelvic support. Pneumatic height adjustment accommodates most desk sizes to let you sit at your preferred height. Contoured mesh seat incorporates a waterfall design to minimize pressure on the thighs and promote good posture. Injection molded, nylon arms are contoured for maximum comfort. Sturdy nylon base with standard, dual-wheel casters allow you to easily adjust your position as needed. Black.