Tough, aggressive and light weight Dyna-Sys 10-speed SLX rear derailleur using revolutionary features from XT and XTR at an affordable price pointShimanos new Direct Mount Rear Derailleur system gives more space around the rear frame dropout resulting in easier rear wheel removal but also allows frame designers to shorten chain stays, increase axel sizes and move suspension pivotsDirect Mount gives a simpler, cleaner lookShadow features a super low profile design that reduces the risk of damage from trail side hazardsSingle tension spring prevents contact with the chainstay resulting in a silent rideDirect cable routing prevents snagging from any trail side hazardsAlloy and steel construction leads to lower weightTwo fluorine-coated link pin bushings aid slick shiftingHigh rigidity wide outer link braces the pulley body to increase pivot joint rigidityStrong return spring for a positive shifting feelImproved cable pull ratio provides a more accurate shift actionDyna-Sys 10-speed compatible only35T capacity GS cageTop normal spring uses the spring to select higher gears.