Shimano's Deore XT Rear Derailleur uses cold-forged construction and cutting edge technology to deliver crisp shifting, real-world reliability, and trademark precision. Plus-type derailleurs use a lever-actuated clutch spring to prevent chain slap, reduce noise while on the trail, and improve chain engagement when riding over rough terrain. Sealed pulley bearings keep things spinning smoothly, and wide plate construction prevents the derailleur from getting clogged with mud and debris.