[High Quality Material]The rear derailleur guide wheel is made of high quality aluminum alloy and ceramic, which is strong, lightweight and durable. [Easy to Install]The rear derailleur guide wheel comes with 2pcs accessories.It is more convenient for you to install.It is practical accessories for bicycle. [Size]The length is about 55mm/2.2in, the installation size is about 6mm/0.24in Axis, the small variable ring diameter is about 4mm/0.16in and the large variable ring diameter is about 5mm/0.20in. [Application]The rear derailleur guide wheel is suitable for most bikes of 11T.It can be used for folding bikes, mountain bikes, road bikes and so on. [Various Speed Changes]The rear derailleur guide wheel supports various speed changes.It can spin very freely and has low friction.It can provide you with a better riding experience. Feature: 1. Strong and lightweight rear derailleur guide wheel, ceramic bearings ensure reliable durability. 2. Support various speed changes. To provide you with a better riding experience. 3. Applicable to most mountain bikes. Suitable for bicycles, road bikes, folding bikes, etc. 4. 15T bike guide pulley, high lubricity, good performance, practical accessories for bicycle. 5. Adopts high quality aluminum alloy and ceramic materials, wear resistant, sturdy and durable. Specification: Item Type: Rear Derailleur Guide Wheel Material: Aluminum Alloy + Ceramic Bearing Type: 15T Length: Approx. 55mm/2.2in Installation Size: Approx. 6mm/0.24in Axis Small Variable Ring Diameter: Approx. 4mm/0.16in Large Variable Ring Diameter: Approx. 5mm/0.20in Package List: 1 xRear Derailleur Guide Wheel 2 x Accessory Note: Please allow 02mm error due to manual measurement. Thanks for your understanding.