1) Office chair part,chair part,furnituer part,office furniture part 2) Office chair gas spring,chair ... 120 / 140 / 160 / 180 / 200 / 260mm,etc.2. Function:Height adjustment,up and down freely,no noise,swivel ... testing,bushing testing) + TUV safety certification(class 2/class 3/class 4)6. General use: office ... s requestment8. Inner tube thickness:1.5mm/2.0mm/2.5mm with hard chromed or QPQ finishment9. ...