Replacement Universal Office Chairs Gas Lift Cylinder - 11.4 to 16.3 inch Adjusts (Silver) Fits Most Office Chairs Outer cylinder diameter: 2 inches, Inner cylinder diameter: 1.1 inches Minimum length: 11.4 inches. Maximum length when fully extended: 16.3 inches Heavy Duty Construction. Net weight: 1015g Smooth 360 degree rotation, smooth and noiseless movements to all directions