Shimano XTR Di2 RD-M9250 Rear Derailleur Pulley Set Description: The Shimano XTR Di2 RD-M9250 Rear Derailleur Pulley Set is a factory replacement set that consists of a tension and a guide pulley. Each of these pulleys feature 13 teeth and a durable plastic body that reduces the noise of the chain going through the derailleur as well as a sealed bearing to ensure long lasting, quiet, and smooth operation. Features: Includes the guide and tension pulleys, covers, and the sealed bearings that the pulley wheels roll on Pulley Bolts and other hardware sold separately