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, anticorrosion 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 AdapterMaterial: Aluminum AlloyColor: BlackSpecification: Front 15MM hub barrel shaft to open 100mm to 110mmFront Hub Adapter Thickness: Approx.5mm or 0.20inFront Spacer Thickness: Approx.5mm or 0.20inOuter Diameter: Approx.5.2cm or 2.0inInner Diameter: Approx.3.9cm or 1.5inApplication: 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 ScrewNote:1. Please allow 12mm 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.