Robust MaterialThis fork stem extender made of 6061 aluminum alloy, is 20% lighter than ordinary aluminum alloy stem extender. Strong in anti-corrosion and rust-free, high toughness and not deformed. Adjustable HeightThe height of the extender can be adjusted by adjusting the number and type of spacers, reducing the pressure of waist effectively, biking more relaxed. Take the discomfort away from your upper back, neck and wrist. Applicable BicyclesThis bike head up adapter fits for most road bikes, mountain bikes, track bikes, mtb, bmx, dh etc, suitable for modifying and upgrading your bike. Functional GasketsThe stem riser adapter comes with 4 spacers (25mm & 210mm), so you can adjust the height of the stem by swapping spacers. Easy InstallationJust use this bike handlebar extender to connect up the original front fork stem, tighten all bolts up with the hex keys.