Shimano SLX RD-M670 Rear Derailleur Bracket Axle Unit Description: The Shimano SLX RD-M670 Rear Derailleur Bracket Axle Unit is a factory replacement part that connects a rear derailleur body to a bicycle's derailleur hanger. If the stock bracket axle kit has become damaged, this replacement part will help to properly align the body of the rear derailleur for optimal shifting performance. Features: Includes the bracket, the bolt that goes into the derailleur hanger, the B-Axle bolt that attaches the bracket to the rear derailleur body, and the hardware to keep the B-Axle attached to the bracket