Deore M6100 Shadow plus 12-speed rear derailleur for dependable shifting performance and durability. Shadow plus features a super low profile design and optimized slant angle for super light shifting action and a chain stabilising switch that when on will reduce chain bounce in rough terrain maintaining more stable drive and shifting.Key Features:Single 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 cageTop Normal SGS Long Cage