Mid-Back Mesh Synchro Knee-Tilter – Pneumatic seat height adjustment. Height adjustable lumbar support. Tilt-tension adjustment. Fixed backrest. Synchronized seat and back movement in a 2:1 ratio and multi-position tilt-lock control. Molded foam seat cushion. Height adjustable armrests with urethane arm caps. Dual wheel casters good for carpets or hard floors. Black upholstery. Comes ready to assemble.