Easy to install and replce,good accessories for your bike. Features: Diameter: 451mm/17.8in.Drop out length: 100/135mm. 2 bearings for front hubs and 4 bearings for rear hubs.Compatible with 8/9/10/11 speed. Made of high strength aluminum alloy material,durable to use. Reinforced brake edge for increased durability. Univesial Presta valve,easy to inflate and replace your tire. Inner tyre cushion effectively protects your inner tyre(not included). Come with a front quick release skewer and a rear quick release skewer. Specification: Material: Aluminum alloy Diameter: 451 mm / 17.8 in Rim depth: 40 mm / 1.6 in Drop out length: 100/135mm Bearing quantity: (front hub)2pcs , (rear hub)4pccs Spokes hole quantity: (front wheel)16pcs , (rear wheel)21pccs Compatible with: 8/9/10/11 speed Wheelset weight: approx. 1507 g / 3.3 lb (not includes quick release skewers) Quick release skewer weight: approx. 100 g / 0.2 lb (for a pair) Package weight: approx. 2837 g / 6.3 lb Package List: 1* Pair of Front&Rear Wheelset 1* Pair of Front&Rear Quick Release Skewer