Features: Made of good quality aluminium alloy, sturdy, non-deformation, features high strength, resistant to high temperature and abrasion, durable for long time use. Ultralight, lighter than other material skewers, 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 9mm quick release skewer. Nice accessory for your bike. Specification: Material: Aluminuim Alloy Color: Black, Silver (Optional) Outer Diameter: Approx. 12mm / 0.47inch Inner Diameter: Approx. 9mm / 0.35inch Length: Approx. 99.8mm / 3.93inch Weight: Approx. 23g Package List: 1 * Bike Quick Release Thru Axle Hub Adapter