Specification: Condition: 100% brand new Item type: Bike Rear Derailleur Pulley Material: aluminium alloyColor: colorful Optional type: 11T, 13T 11T diameter: Approx. 41mm/1.6in 13T diameter: Approx. 49mm/1.9in Specification: applicable to the guide wheel of 4/5/6mm axis. Guide wheel selection rules: Please try to choose the same as the original guide wheel, if there is no same, you can choose smaller than the original guide wheel, can not choose a larger one. Applicable: for micro rear derailleur Package List: 1 Set x Bike Rear Derailleur Pulley