Acera RD-M3020-SGS Rear Derailleur - 7/8 Speed, Long Cage, Black

The Shimano Acera RD-M3020 rear derailleur features Double Servo technology to provide smooth, precise shifting and helps you ride challenging terrain with fewer interruptions.

• Double Servo mechanism enables the rear derailleur to move in an optimum path
• Versatile performance and wide compatibility
• SGS Long cage