Shimano Deore RD-M5100 Rear Derailleur Pulley Set Description: The Shimano Deore RD-M5100 Rear Derailleur Pulley Set is a factory replacement set that consists of a tension and a guide pulley. Both of these pulleys feature 13 teeth and a plastic body that reduces the noise of the chain going through the derailleur. Features: Includes the guide and tension pulleys, covers, and the low maintenance bushings that the pulley wheels roll on Guide Pulley Bolts and other hardware sold separately