Sram: THE NEXT GENERATION OF SRAMThe SRAM GX 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, 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 everTHINGS TO REMEMBER• This GX rear derailleur is an integral part of the SRAM 1x™ drivetrain system. NO COMPROMISES.FEATURES AND BENEFITS• X-HORIZON™ design reduces shift force, ghost shifting and cage slap• 12-tooth X-SYNC™ pulley wheels• Large upper pulley offset automatically adjusts chain gap• Sealed cartridge bearings• Aluminium cageSPECIFICATIONSSpeed (RD):  11sCable pull ratio:  X-actuationCage (RD):  LongMax tooth:  42Colour (RD):  Black, RedPulley bearings material:  SteelCage material (RD):  Aluminium