The all-new Shimano Deore M6100 rear derailleurs deliver advanced shifting performance with decreased tension in the low gear position. Larger 13T pulleys increase efficiency and chain management while compatibility with Shimano's new 12-speed cassettes boosts range.Deore M6100 Shadow plus 12-speed rear derailleur for dependable 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 chainstay resulting in a silent ride13T pulleys and decreased derailleur tension prevent high chain tension in low gearsDirect cable routing prevents snagging from any trail side hazardsCold forged wide alloy links and pivot bodyFluorine-coated link pin bushingsStrong return spring for a positive shifting feelDurable 13T bearing pulleys for low frictionTop normal spring uses the spring to select higher gearsMax low sprocket: 51T (1x 12-speed)41T capacity SGS cage