[High-quality materials]: The bicycle handlebar riser is made of high-quality high-strength aluminum alloy material, and the workmanship is strict and exquisite. The matte process makes the surface more texture.[Adjustable height]: The height of the bicycle rod can be adjusted freely, and 4 shims can be used in various ways. You can adjust the new stem height completely according to your driving requirements.[Safe and stable]: The handlebar is fixed by double screws, making the handlebar more firm and not easy to fall off, and safe use is more assured.[Easy to install]: Just slide the spindle extender onto the steering tube and tighten, it is very easy to assemble.characteristic:Colour: Black.Material: Aluminum alloy.Size: about 12cm x 3.5cm (including lid 12.4cm)Upper size: 2.8cm, inner 2.2cmLower size: 3.5cm, inner 2.8cmThe diameter is 28.6 mm (universal caliber)