The SLX M7100 series of derailleurs deliver advanced shifting performance with decreased tension in the low gear position and an added bumper on the pulley cage. Larger 13T pulleys increase efficiency and chain management while compatibility with SHIMANO's new 12-speed cassettes boosts range. FEATURES Advanced shifting performance provides the confidence to enjoy any trail Fast and shockless shifting HYPERGLIDE+ Extra wide range 12-speed drivetrain -10-51T (12-speed) Silent drivetrain in all gear positions Decreased rear derailleur and chain tension in low gear Bumper structure at rear derailleur pulley cage reduces impact shock by absorbing chain impact on aggressive terrain Bigger 13T pulley Stable drivetrain on rough terrain Low-profile design SHIMANO SHADOW RD+