Boss Office Products B8601 High Back No Tools Required LeatherPlus Chair in Black NTR- No tools required for assembly Beautifully upholstered with LeatherPlus (leather that is polyurethane infused for added softness and durability) Waterfall seat design eliminates leg fatigue; Ergonomic back design with lumbar support Upright locking position; Adjustable tilt tension. Optional knee-tilt mechanism