The SRAM NX X-HORIZON™ rear derailleur gives the same smooth, reliable shifting action as XX1—from the larger upper pulley offset to the 12-tooth X-SYNC™ pulley wheels. By eliminating unwanted chain movement, X-HORIZON™ 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.X-HORIZON™ design that reduces shift force, ghost shifting and chain slap,12-tooth X-SYNC™ pulley wheels,Fully compatible with all SRAM 1x™ drivetrains,Most affordable fully featured 1x rear derailleur in the industry.