Features 1、Strong and Durable: Made of CNC aluminum alloy, light weight, rust resistant, corrosion resistant, and anodized. 2、Two Wheel Models: Guide wheel adopts a circlip fixed structure, which is compatible with the guide chain wheel and the tension wheel. 3、Strong Compatibility: To meet different sizes, 10 teeth are suitable for 8, 9, 10, 11 speed rear derailleur, and the outer diameter of the installation shaft is compatible with 4, 5, and 6mm. 4、Smooth Rotation: Zirconia ceramic balls are used, which are self lubricating and maintenance free. At the same time, the transmission efficiency is higher and the riding is labor saving. 5、New Design of Circlip: With the new fixed structure of circlip, it solves the problem of chain jam and guarantees smooth speed change and stable operation of the rear derailleur. Specification Item Type: 10T Rear Dial Guide Wheel Color: As Pictures Shown Weight: Approx.9g/0.3oz Material: Aluminum Alloy + Ceramic Ball Package List 1 x Rear Dial Guide Wheel 2 x Reducing Sleeve