[Adjustable Height 4 inches]The sinking length is 2.4" (60mm), lowering the chair's minimum height, as a replacement for people needing a shorter chair. Compressed height is 7.48 inches (190mm), the fully expanded height is 11.2 inches (284mm), Stroke Length is 4 inches, which allows your chairs to rise higher. [Universal Fit Size for Most Chairs]The outer column cylinder diameter connected to the base is 2 inches (50mm), and the piston shaft diameter connected to the chair is 1-1/8" (28mm). This pneumatic piston cylinder fit almost every office chair on the market. [Upgraded Class 4 Gas Cylinder]office chair cylinder replacement is made of premium steel, the lift has a maximum capacity of up to 1000 lbs. [ Sinking Concerns]Prevent sinking issues by removing the old cylinder using a hammer or wrench. Simply assemble our cylinder into the base and attach the seat. Our office chair lift provides seamless 360-degree rotation. [100% Satisfaction Guaranteed]For any issues with using our chair shock replacement, please don't hesitate to contact us. We are here to provide guidance, offer replacements, or process refunds, depending on your specific case. Your satisfaction is our priority. Color: Black Material: Metal Package Contents: 1*Chair Cylinder Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.