SRAM GX Rear Derailleur - 10 Speed Long Cage BlackSRAM GX Rear Derailleur 10 Speed Long Cage Black. SRAM GX rear derailleur takes the place of X. 9 and X. 7 10 speed models and provides shifting speed and precision. Exact Actuation technology eliminates slop and shifting variation Roller Bearing Clutch delivers maximum drivetrain stability even through the most punishing terrain TECH SPECS Largest Cog 36 Color Black Rear Der Shifter Compatibility SRAM Exact Actuation Rear Derailleur Mount Type 10x1