Feature: 1. Suitable for the front hub barrel shaft to open 100mm to 110mm, and the quick release device is used to install and fix the wheels. 2. Made of high quality aluminum alloy material, anti‑corrosion and not easy to deform, sturdy and durable. 3. Original standard, direct replacement for old or broken one. Ensures wonderful brake performance. 4. Comes with necessary accessories, spacer and screws, easy to install and convenient to use. 5. In order to adapt to the corresponding disc brake disc position and the demand of opening gear, solved the problem of compatibility between hub and front fork and frame. Specification: Item Type: Boost Hub Adapter Material: Aluminum Alloy Color: Black Specification: Front 15MM hub barrel shaft to open 100mm to 110mm Front Hub Adapter Thickness: Approx.5mm / 0.20in Front Spacer Thickness: Approx.5mm / 0.20in Outer Diameter: Approx.5.2cm / 2.0in Inner Diameter: Approx.3.9cm / 1.5in Application: Suitable for the front hub barrel shaft to open 100mm to 110mm, in order to adapt to the corresponding disc brake disc position and the demand of opening gear, solved the problem of compatibility between hub and front fork and frame. . Package List: 1 x Boost Hub Adapter1 x Pair of Spacer6 x Screw Note: 1. Please allow 1‑2mm error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.