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