Gas spring or cylinder for Various chairs 1.Pass SGS test 2.100000 ... ,160,230,260,3303. Surface: Black,Chrome 4. Standard: Class 2,Class3,Class 4 5. SGS BIFMA X5.1(100, 000 Times ... . Warranty: 5 years 9. OEM Service10.ISO9001 Certificate. gas spring or gas cylinder for a variety of chairs