Description The Shimano RD-M3020-8 Acera 7/8-Speed Rear Derailleur is a double Servo rear derailleur with smooth, precise shifting performance and wide-range capability. Double Servo technology helps you ride challenging terrain with fewer interruptions. Features Double Servo construction for smooth and precise shifting Versatile performance and wide compatibility Max. low sprocket: 40T Total capacity: 45T Does not work with 11-28T drivetrains
