Technology: aluminum alloy plating. Fabric: full leather / half leather /PU (optional). Base: aluminum alloy five-star base with zinc electroplating nylon wheel. Gas lift: According to different kinds of the gas lift. Chassis: Knee-tilt mechanism, with gas lifting and knee-tilt function which can adjust the elasticity of knee-tilt to meet with different weight of users. Seat back: simple and graceful design which according to the characteristics