The Shimano m9100 XTR 11-12spd rear derailleur has the ultimate in shifting performance and durability Shimano m9100 XTR 11-12spd rear derailleur Shadow plus features a super low profile design and optimized slant angle for super light shifting action Shadow Plus uses a chain stabilising switch that when on will reduce chain bounce in rough terrain maintaining more stable drive and shifting Single tension spring prevents contact with the chainstay resulting in a silent ride Rubber bumper on pulley cage for added silent drive 13T pulleys and decreased derailleur tension prevent high chain tension in low gears Direct cable routing prevents snagging from any trail side hazards Full carbon fibre outer pulley cage saves weight while alloy inner cage increases rigidity Cold forged wide alloy links and pivot body Four fluorine-coated link pin bushings Strong return spring for a positive shifting feel Specifically designed to work with XTR M9100 12-speed 1x drivetrains Durable sealed 13T bearing pulleys for low friction Top normal spring uses the spring to select higher gears >Max low sprocket: 45T (1x 12-speed) 35T capacity SGS cage Average weight 237g