1, Gas Spring / Gas Lift / Gas Cylinder / Office Chair parts / Bar Stool / Table 2. Stroke(mm): 80 / 100 / 120 / 140 / 160 / 230 / 260 / 330,Etc. 3. Surface: Black / Chrome 4. Standard: Class 2/ Class 3/ 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: 5years 9. OEM Service/ ISO9001 Certificate