Precision engineered XTR Shadow Dyna-Sys 10-speed rear derailleur for the ultimate in shifting performance & durability Shimanos 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 & move suspension pivots Direct Mount gives a simpler cleaner look Shadow features a super low profile design that reduces the risk of damage from trail side hazards Single tension spring prevents contact with the chainstay resulting in a silent ride 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 alloy links & pivot bodys with carbon composite P-body Four fluorine-coated link pin bushings High rigidity wide outer link braces the pulley body Strong return spring for a positive shifting feel enhanced cable pull ratio provides a more accurate shift action Dyna-Sys 10-speed compatible only Durable sealed bearing pulleys for low friction Top normal spring uses the spring to select higher gears 35T capacity GS cage