1.Gas Cylinder,Spring,Lift for Chair 2.100.000 times up and down,360 revolve 3.Smooth,noiseless 4.Easy to fix ... and adjust 1, Gas Spring / Gas Lift / Gas Cylinder / Gas Strut for Office Chair ... / Bar Stool / Table2. Stroke(mm): 80 / 100 / 120 / 140 / 160 / 230 / 260 / 330,Etc.3 ...