Xt shadow plus 12-speed rear derailleur for fast and precise shifting performance optimized to take on any trailshadow 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 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 hazardscold forged wide alloy links and pivot bodyfour fluorine-coated link pin bushingsstrong return spring for a positive shifting feelspecifically designed to work with 12-speed 1x drivetrainsdurable sealed 13t bearing pulleys for low frictiontop normal spring uses the spring to select higher gearsmax low sprocket: 51t (1x 12-speed)41t capacity sgs cageaverag