Made of high-quality materials, durable.The front hub for mountain bikes is a 20mm barrel hub that needs to be converted into a 15mm barrel hub for easy use.This product is directly inserted into the barrel hub and it becomes a 15mm barrel hub.Type 1 is designed for 100mm barrel shaft, and the type 2 is designed for 110mm barrel shaft.Type: Barrel ShaftMaterial: Aluminum Alloy 100mm/110mmFeatures: Aluminum Alloy, Durable, Bicycle ToolOuter Diameter: 2cm/0.79" (Approx.)Inner Diameter : 1.5cm/0.59" (Approx.)Notes:Due to the light and screen setting difference, the item& 39;s color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Barrel Shaft When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don't hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it!