Bicycle Small Parts Bike Hub Conversion Front Rear Bicycle Hub Conversion Adapter Bicycle Accessory Features: Made of aluminium alloy material,high strength,anti-rust and durable. Easy to change 100 * 15 mm front hub into 110 * 15 mm,Or change 142 * 12 mm rear hub into 148 * 12 mm. (optional) Comes with necessary fittings,easy to install and use Useful accessory for bike lovers. Specification: Model: 44 * 3 mm / 44 * 5 mm (optional) Color: Red / Black (optional) Material: Aluminum Alloy 44 * 3 mm: Fits to change 142 * 12 mm to 148 * 12 mm (for rear hub) 44 * 5 mm：Fits to change 100 * 15 mm to 110 * 15 mm (for front hub) Weight: Approx. 24.4-28.1g / 0.9*1.0oz Package List: 1* Hub Convension Adapter 2* Spacers 6* Screws NOTE: The blue gel on the screws is to prevent from loosening easily,but not to impact the quality and quantity.