Gas spring or cylinder for Various chairs 1.Pass SGS test 2.100000 times fatigue test 3. ... Surface:Black,Chrome 4.free sample 1.Gas Lift,Gas Spring ,Gas Cylinder,Gas Strut for Office Chair,Bar Stool,Table 2 ... Standard: Class 2,Class3,Class 4 5. SGS BIFMA X5.1(100, 000 Times Testing) 6.Pressure(N): 300--450 7 ... 9. OEM Service10.ISO9001 Certificate. gas spring or gas cylinder for a variety of chairs