The Best Build Quality & Perfectly Ergonomic. Leather Head And Lumbar Back Rest. Multi-Functional Tilt Mechanism. 2D Strong Bow Shaped Armrest. Finest Core Materials. Easy Backrest Recline. Durable PU Wheels Smooth Casters, Stability and Safety Class 4. Hydraulic Pistons. Strong Nylon Plastic Base, Designed To Hold Up To 150KG.