Every detail of the 11-speed X1 X-HORIZON rear derailleur from Sram is engineered for smooth, reliable shifting action. From the larger upper pulley offset to the 12-tooth X-SYNC pulley wheels, every part is designed to eliminate unwanted chain movement. This means that the X-HORIZON shifts faster, puts an end to ghost shifting, and reduces shift force and chain slap. With the CAGE LOCK technology, wheel removal and installation are easier than ever. Trust Sram for a high-quality rear derailleur.