MySit Office Chair Piston Gas Lift Cylinder | Heavy Duty 5" Stroke Universal Size Pneumatic Chair Cylinder Gas Spring Rod Replacement Black (GasLift120_BLK) &hellip; Class 4 level, Top Quality Level, Heavy Duty Construction, Specialized for Heavy Person,BIFMA Plus Quality Height Adjustable range: 5 inches, Outer cylinder diameter: 2 inches, Inner cylinder diameter: 1.1 inches, Fits Most Office Chairs 5 Years Free Replacement or Money Back Guarantee. NOT FIT 40mm Diameter Base Hole.