Boss Office Products Black Contemporary Ergonomic Adjustable Height Swivel Task ChairContemporary ergonomic mesh back designed to provide exceptional back support and to prevent body heat and moisture build up Ratchet back with active lumbar support Height and width adjustable arms 3 Paddle multi function tilting mechanism, which allows the seat and back to be independently adjusted and locked in any position Seat tilt lock allows the seat to lock throughout the tilt range Adjustable tilt tension control Pneumatic gas lift seat height