Thank you for coming to our shop, I hope it is to your satisfaction Item Name: Rear Derailleur Wheel Features: High Strength, Anti-rust, Corrosion Resistant Size Details: 11T: Diameter: 3.4cm/1.34" (Approx.)13T: Diameter: 5.1cm/2.01" (Approx.)15T: Diameter: 6cm/2.36" (Approx.) Specifications: Universal for mountain bikes, road bike, folding bike, etc. Made of premium aluminum alloy and metal material, the rear derailleur is high hardness and corrosion resistant. Deep tooth design makes the rear derailleur guide wheel fit closely with the chain, reducing chain wear, not easy to drop the chain, enabling efficient transmission. Adopt anodized oxidation treatment in the surface layer to prevent the rear derailleur wheel from rusting and oxidation. With the characteristics of anti-deformation and wear-resisting, it is sturdy and durable and has a long service life. There are three different sizes for you to choose: 11T, 13T, 15T. Kindly Remind: Due to light and display, there may be slight differences between the picture and the actual color of the product. The color is subject to the goods received. In addition, please allow slight size difference due to manual measurement. High quality, assured choice is guaranteed Package Includes: 1 x Rear Derailleur Wheel 2 x Reducer Sleeves