NTR- No tools required for assembly. Beautifully upholstered with LeatherPlus. LeatherPlus is 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. Pneumatic gas lift seat height adjustment. Optional knee-tilt mechanism available model (B8602), (assembly required).