Feature:1. The product is made of aluminum alloy, which is strong and not easily deformed.2. For 31.8mm diameter stem, thinned to fit 25.4 mm handle.3. For 25.4mm diameter stem, thickened to fit 31.8mm handle.4. Easy to install, easy to fix, and recyclable, provide good usage experience for you.5. Universal, easy to install and remove. Suitable for mountain bike, road bike, etc.Specification:Item Type: Bike Handlebar Shim AdapterMaterial: aluminium alloy Color: As Pictures Shown Product Size: Approx. 37x23mm/1.5x0.9inThickness: Approx. 3.1mm/0.1inWeight: Approx. 51g/1.8oz Package List:4 xHandlebar Stem Reducer Note:1. Manual measurement, please allow 10mm error, thank you!2. The picture may not reflect the actual color of the project due to the differences between different displays.