1、Lightweight Design: The hub body is made of high quality AL-6061 aluminum alloy with high strength and light weight. 2、Aluminum Alloy Cassette Body: 7075 aluminum alloy cassette body has compact structure, which enhances wear resistance and good corrosion resistance. 3、Product Features: High speed rotation, the ratchet teeth bite tighter, during the pedaling process, the pawl can bite the ratchet teeth when pedaling at a small angle, reducing the loss of force. 4、Quick Release Design: Easy to install, it can directly replace the old quick release hub. With quick release lever, it can be quickly disassembled and installed. 5、Specification: Front 2 rear 4 bearings, front: 9x100mm / 0.4x3.9 inch, rear: 10x135mm / 0.4x5.3 inch, 32 holes. Item Type: Mountain Bike Front Rear Quick Release Hub Material: Aluminum Alloy Front Hub Opening Size: Approx. 9x100mm / 0.4x3.9in Rear Hub Opening Size: Approx. 10x135mm / 0.4x5.3in Front Hub Diameter: Approx. 68mm / 2.7in Rear Hub Diameter: Approx. 68mm / 2.7in Front Hub Ear Distance: Approx. 62mm / 2.4in Rear Hub Ear Distance: Approx. 58mm / 2.3in Product Weight: Approx. 814g / 28.7oz Bearing: Front 2 Rear 4 Bearings Number of Holes: 32 holes Cassette Body: Aluminum alloy cassette body, 8/9/10 speed cassette can be directly installed, 7 speed cassette needs to add gaskets, M8000 11 speed cassette can be directly installed. 1 x Front Quick Release Hub 1 x Rear Quick Release Hub 1 x Front Quick Release Lever 1 x Rear Quick Release Lever 1 x Washer