... .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 ... ,Chrome 4. Standard: Class 2,Class3,Class 4 5. SGS BIFMA X5.1(100, 000 Times Testing) 6.Pressure(N): 300--450 ... 7.Bottom Color: White,Black,Orange,Blue,Gray,Green 8. Warranty: 5 years 9. OEM Service10.ISO9001 Certificate. gas spring or gas ...