Features1Suitable for the front hub barrel shaft to open 100mm to 110mm, and the quick release device is used to install and fix the wheels. 2Made of high quality aluminum alloy material, anticorrosion and not easy to deform, sturdy and durable. 3Original standard, direct replacement for old or broken one. Ensures wonderful brake performance. 4Comes with necessary accessories, spacer and screws, easy to install and convenient to use. 5In 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.SpecificationItem Type: Boost Hub AdapterMaterial: Aluminum AlloyColor: BlackSpecification: Front 15MM hub barrel shaft to open 100mm to 110mmFront Hub Adapter Thickness: Approx.5mm / 0.20inFront Spacer Thickness: Approx.5mm / 0.20inOuter Diameter: Approx.5.2cm / 2.0inInner Diameter: Approx.3.9cm / 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 List1 x Boost Hub Adapter1 x Pair of Spacer6 x Screw