... test 3.Surface:Black,Chrome 4.free sample 1.Gas Lift,Gas Spring ,Gas Cylinder,Gas Strut for Office Chair,Bar Stool,Table ... ,140,160,230,260,3303. Surface: Black,Chrome 4. Standard: Class 2,Class3,Class 4 5. SGS BIFMA X5.1(100, 000 ... years 9. OEM Service10.ISO9001 Certificate. gas spring or gas cylinder for a variety of chairs