Shimano xtr m9050 di2 11sp rear derailleurshimano's first mountain bike specific di2 rear derailleur is also its most technologically advanced'. '.strtoupper('i')ntroducing shimano shadow rd stabilization to di2, the rd m9050 couples unrivaled chain control that aggressive riders have come to love with shift performance that doesn't degrade over time.whether cross country or trail riders run a 1x, 2x or 3x drivetrain, the ultra narrow profile help protect the drivetrain in tight trail sections'. '.strtoupper('t')he refined rear derailleur geometry further improves the performance stability while shimano synchronized shift enables system communication with the front derailleur.unrivaled shift and performance stability shimanos xtr m9050 di2 rear derailleur delivers unrivaled chain control and shift performance that doesnt degrade over time'. '.strtoupper('w')ith shimano shadow rd clutch technology, the rd m9050 is the ultimate mountain bike rear derailleur'. '.strtoupper('i')ts profile is narrower than ever, helping you squeeze through tight sections without worry of damage'. '.strtoupper('a') refined geometry augments shimanos already legendary performance stability while system communication with the front derailleur makes shimano synchronized shift a possibility.featuresinstantaneous shift response to rider inputseamless gear changesshimano synchronized shift compatiblesystem communication with front derailleuradvantage in all conditionse tube electric wire transmission guarantees stable performancelow profile positions rd safely away from trail obstacles1x, 2x and 3x compatible with gs and sgs cage optionsspecificationscage material aluminium mount medium cage or long cageweight 289ga 2 year warranty is offered with all shimano products from chain reaction cycles 3 years on dura ace and xtr products.buy shimano components from chain reaction cycles, the world's largest online bike store.