Made of high quality aluminium alloy, sturdy, non-deformation, features high strength, resistant to high temperature and abrasion, durable for long time use. Ultralight, adding no burden to bike, good for reducing the weight of bike. Tool-free installation, just insert the adapter into the thru axle hub. It converts 12mm thru-axle hub to standard 10mm quick release skewer. Great accessory for your bike. Specification: Material: Aluminuim Alloy Color: Black Outer Diameter: Approx. 12mm / 0.47inch Inner Diameter: Approx. 10mm / 0.35inch Length: Approx. 135mm/142mm/145mm Package Includes: 1 Piece Bike Quick Release Thru Axle Hub Adapter(2 Pack) Note: 1. Please allow a slight color difference between the real item and the pictures due to the difference between monitors. 2. Please allow a slight measurement error. Hope for your kind understanding and have a nice shopping day!