Gas spring or gas cylinder for office chair 1.Pass SGS test 2. ... for Office Chair,Bar Stool,Table 2. Stroke(mm): 80,100,120,140,160,230,260,3303. Surface: Black,Chrome 4 ... : Class 2,Class3,Class 4 5. SGS BIFMA X5.1(100, 000 Times Testing) 6.Pressure(N): 300--450 7.Bottom ... . Warranty: 5 years 9. OEM Service10.ISO9001 Certificate. gas spring or gas cylinder for Office Chair and bar chair