Staff chair:electroplate frame(MOQ:50PCS) mesh,black nylon for outside back. 50kg/CBM one time shaping PU foam, PP armrest,PP dust-proof cover,PP inside back.armrest support made by ∮22*T2.0 round tube, feet made by moulded triangle tube. Tube size:30*30*T2.0, 12cm thick seat. 386base, have lift, tilt and lock function, all are laquered colour. Nylon castor(size:∮50MM.castor has no broken under 50000times resistance and fatigue test). Andco 80*80 gas lift bar,it can stretch out and draw back 120000times without leak.