Aluminum Alloy & High Quality -Anodized aluminum alloy construction, solid, strong, corrosion-resistant and rust-free. Adjustable -Help to extend the fork stem by 70 mm / 2.8 in maximally.The height can be adjusted by adjusting the number and type of gaskets, making it easier to hold traction on the steep hill. Easy Installation - Just connect up the original front fork stem and done to install. Widely Compatible - Don't worry about buying a handlebar adapter that doesn't fit your car. Suitable for mountain bicycle to rise up the handlebar fork stem..For 28.6 mm / 1.1 in front fork. Light weight make Operation Convenient - The aluminum alloy bicycle stem riser is 20% lighter than ordinary all alloy stem extender. Handling more flexible,much easier to force when climbing, operation is comfortable and convenient Specifications: Colour: Black Material: aluminium alloy. Base diameter: 1-1/8 inch (28.6mm). Fork stem diameter: 28.6mm (standard). Length: 12cm /4.7 inches. Weight: 191g / 6.7oz. Package includes: 1 x bicycle fork stem extender. Installation instructions: 1. Insert Stem-Up into the hole and adjust the height of the Stem-Up to your preferRed level. 2. With stem and wheel in the same direction, raise clamping screw of the stem.