Six different colors allow you to choose your favorite one according to your preference. Professional and exquisite workmanship makes it very wear-resistant and durable.The deep tooth design makes it possible to effectively reduce the chain drop. Three different specifications allow you to choose the most suitable one according to your needs.Made of aluminum alloy and steel, it is very durable to use.There are three specifications for you to choose from: 11T, 13T, 15T.Equipped with a reducing sleeve, the compatibility is stronger, the original hole diameter is 6mm, and the installation reducing sleeve can be converted into a 4mm or 5mm bearing for flexible rotation.Item Name: Bicycle Rear Derailleur WheelMaterial: Steel,Aluminum AlloyStyle: Steel BearingSuitable For: 4/5/6mm AxleFeatures: High Strength, Deep Teeth, Wear-resistantSize Details: 11 T: Diameter: 4.15cm/1.63" (Approx.)13 T: Diameter: 5cm/1.97" (Approx.)15 T: Diameter: 6cm/2.36" (Approx.)Notes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Bicycle Rear Derailleur Wheel1 x Guide Wheel Screw2 x Reducer Sleeves