Shimano ACERA M3020 rear derailleur with Double Servo technology for precise shifting with a wide range. 45 teeth. For cassette with largest pinion 40z.
MTB, Total Package Weight: 424g, 7/8 speed, Shackle Type: SGS-Super Long Shackle, Mounting Type: Direct Mount, Capacity: 45 teeth, Black, Material: Aluminum/Steel