Model number: T839E Size:Standard Chair Cover Material:Mesh Arm Type : Adjustable 2D armrest(up&down, front&back) Mechanism Type: Tilting mechanism with 3 level locking function Gas Lift: 100mm class 3 Base: R340mm Aluminum alloy Base/R340mm Nylon Base Casters : 60mm Caster/PU Frame: PA Nylon Foam Type: molded Foa