The SRAM GX X-HORIZONrear derailleur is engineered for smooth, reliable shifting actionfrom the larger upper pulley offset to the 12-tooth X-SYNCpulley wheels. By eliminating unwanted chain movement, X-HORIZONshifts faster, puts an end to ghost shifting and reduces shift force and chain slap. And with CAGE LOCKtechnology, wheel removal and installation are easier than ever.THINGS TO REMEMBERThis GX rear derailleur is an integral part of the SRAM 1xdrivetrain system. NO COMPROMISES.FEATURES AND BENEFITSX-HORIZONdesign reduces shift force, ghost shifting and cage slap12-tooth X-SYNCpulley wheelsLarge upper pulley offset automatically adjusts chain gapSealed cartridge bearingsAluminium cageSPECIFICATIONSSpeed (RD): 11sCable pull ratio: X-actuationCage (RD): LongMax tooth: 42Colour (RD): Black, RedPulley bearings material: SteelCage material (RD): Aluminium