8T8 4" Office Chair Gas Lift Cylinder Replacement, Universal Size Hydraulic Pneumatic Piston Shock (Black 100) HEAVY DUTY - Made of high quality metal construction, support more weight and pressure than other original standard gas cylinders UNIVERSAL STANDARD SIZE - 2 inch bottom base and 1.1 inch cylinder shaft fit most executive, office, computer and desk chairs Hold the maximum weight over 450 lbs and lift the height to 4 inches, as well as allow for 360 degrees quietly swiveling Easy to install: Both cylinders' edges are slightly tapered for easily installing, you can use your home repair kits simply to remove the old cylinder and install the new cylinder There are 5 Sizes and 2 Colors (Black/White) of office chair gas lift cylinders for your choosing, please determine what sizes and colors you want before you add to cart, and we promise providing friendly customer service