Specifications: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 AlloySpecifications: 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 items color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement. Package Includes:1 x Barrel Shaft