The M8100 12 speed rear derailleur offers fast and precise shifts on any trail. It features a low profile design to minimise it catching on stray branches or rocks. It also features Shimano's adjustable clutch system and added bump stops for increased chain security and quieter operation even on the bumpiest terrain. Designed for use on Shimano's 12 speed wide range cassette, it can handle a massive 10-51T range, and comes with a larger 13T pulley for quieter shifts and better efficiency. The end result is a derailleur with faster, shock-less shifting, which is quiet throughout all its gear positions.