Features: Made from aluminum alloy to ensure stiffness and durability. Sealed bearings protect the hub from dirt and water. Compatible with 9-13 speed freewheels. Quick release, caps, spacers are included, easy to install and remove. Specifications: Material: Aluminum alloy Holes/Spokes: 32H/14G Bearing: Front 2, rear 4 Front Hub: Quick Release: 100*9mm ; Axle: 100 * 15mm Rear Hub: Quick Release: 135 * 10mm ; Axle: 135 * 12mm; 142 * 12mm Front Hub Weight: Approx. 137g / 4.8oz Rear Hub Weight: Approx. 245g / 8.6oz Quick Release Weight: Approx. 114g / 4oz (1 pair) Package Size: Approx. 20.8 * 16 * 7.5cm / 8.2 * 6.3 * 3.0in Package Weight: Approx. 656g / 1.4lb Package List: 1 * Front Hub 1 * Rear Hub 1 * Pair of Quick Release 2 * Pair of Caps 2 * Axle Cap 1 * Spacer for Rear Hub