Shimano XTR M9120 12sp Rear DerailleurThe Shimano XTR M9120 Rear Derailleur features an elegant, refined and optimised design, which is aimed at providing maximum drivetrain efficiency over the most demanding terrain. The derailleur has been redesigned to ensure that chain tension is decreased when in the low gear position (41T on cassette), which makes shifting easier while the Shadow+ mechanism ensures chain stability. Featuring oversized 13T pulley wheels, updated Shadow RD+ mechanism and is tailored specifically to provide maximum chain retention and shifting accuracy across the new Shimano 12-Speed drivetrain transmission system.Features: Material: Aluminium, Stainless Steel Drivetrain Speed: 12-Speed Low Sprocket Max: 45T Low Sprocket Min: 45T Top Sprocket Max: 10T Top Sprocket Min: 10T Total Capacity: 41T G Pulley Bearings: Sealed Link Bushings: Fluoric coated Pulley Teeth: 31T Spring Type: Shimano Shadow RD+ Compatible Chain: CN-M9100 Weight: 241gBuy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.