The chair back, base, armrest mould plastic injection is produced independently by our manufacturer. 1. Material instruction:(1) Back: Leather.(2)Seat:Leather.(3) Armrest: PP and metal height adjustable armrest are optional.(4) Armrest Pad: PP and PU are optional.(5) Multifunctional Mechanism(6) Base: Nylon, aluminum and iron chroming base are optional. Aluminum base and iron chroming base can ...