Boss Office Products B3045 Multi-Function LeatherPlus Task Chair without Arms in Black Upholstered in Black LeatherPlus Back angle lock allows the back to lock throughout the angle range for perfect back support Seat tilt lock allows the seat to lock throughout the tilt range Pneumatic gas lift seat height adjustment Nylon base; Hooded double wheel casters Upholstered in Black LeatherPlus Back angle lock allows the back to lock throughout the angel range for perfect back support. . Seat tilt lock allows the seat to lock throughout the tilt range Pneumatic gas lift seat height adjustment Nylon base Hooded double wheel casters Nylon base with hooded double wheel casters