SHIMANO DEORE RD-M5100 11-SPEED REAR DERAILLEURNEW AND IMPROVEDShifting performance is important when you're riding in demanding terrain. Being able to go from a high gear to a low gear quickly will save your legs on those tough climbs. The Shimano Deore RD-M5100 11-Speed Rear Derailleur has been redesigned to work with 11-speed drivetrains. It features Shadow RD+ technology for more stability during aggressive riding and a quieter ride. This derailleur has a maximum cog size of 51T. Features Redesigned for 11-speed drivetrains Shadow RD+ technology for better derailleur stability during aggressive riding and a quieter ride Maximum cog size: 51T | Shimano | Deore Rd-M5100 11 Speed Rear Derailleur Sgs Cage