Features: Material: Bike hub conversion adapter made of quality aluminum alloy materials, high strength, anti-rust, no deformations and durable. Fine Workmanship: CNCmachining makes the outside smooth and can prevent abrasion damage. Changing the Front and Rear: With this adapters, you can change 100x15mm front hub into 110x15mm, and 142x12mm rear hub into 148x12mm. Essential Fitting for You: The front rear boost hub adapter comes with necessary fitting, easily to install and use. Useful accessory for bike lovers to DIY bike. Service: Your satisfaction is our priority. If you are not satisfied with our product or have any questions, please to contact our. Specifications: Material: Aluminum Alloy, Steel Color: As The Picture Shows Style Options: 2 Style are Available as Shown in the Picture. Size: approx.110x15mm/4.33x0.59in Package Includes: 1 Set of Bike Hub Conversion note: Please allow 1-2cm error due to manual measurement. Please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks!