SRAM's GX 1x11 X-Horizon rear derailleur is engineered for smooth, reliable shifting action--from the larger upper pulley offset to the 12-tooth X-Sync pulley wheels. By eliminating unwanted chain movement, this X-Horizon rear derailleur shifts faster, puts an end to ghost shifting, and reduces shift force and chain slap. And with Cage Lock technology, wheel removal and installation are easier than ever. - Long cage - X-Horizon design reduces shift force, ghost shifting, and chain slap - 12-tooth X-Sync pulley wheels - Large upper pulley offset automatically adjusts chain gap - Sealed cartridge bearings - Aluminum Cage