Boss Office Products B7506 Executive Mid Back LeatherPlus Chair in Black Beautifully upholstered in black LeatherPlus LeatherPlus is leather that is polyurethane infused for added softness and durability; Passive ergonomic seating with built-in lumbar support Padded armrests covered with Caressoft upholstery Large 27" nylon base for greater stability; Hooded double wheel casters Upright locking position; Pneumatic gas lift seat height adjustment; Adjustable tilt tension control Beautifully upholstered in black LeatherPlus Passive ergonomic seating with built-in lumbar support. Padded armrests covered with Caressoft upholstery. Pneumatic gas lift seat height adjustment. Optional knee-tilt mechanism available (B7507) Passive ergonomic seating with built-in lumbar support Padded armrests covered with Caressoft upholstery Large 27-Inch nylon base for greater stability Hooded double wheel casters