The M7100 SLX 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.SLX Shadow plus 12-speed double rear derailleur for the ultimate in shifting performance and durabilityShadow plus features a super low-profile design and optimized slant angle for super light shifting actionShadow Plus uses a chain stabilising switch that when on will reduce chain bounce in rough terrain maintaining more stable drive and shiftingSingle tension spring prevents contact with the chain stay resulting in a silent rideRubber bumper on pulley cage for added silent drive13T pulleys and decreased derailleur tension prevent high chain tension in low gearsDirect cable routing prevents snagging from any trail side hazardsFull carbon fibre outer pulley cage saves weight while alloy inner cage