SRAM GX Bicycle Rear Derailleur with 2 x 11 Speed Medium Cage GX provides the widest 2x11 gear range available The GX 2x11 rear derailleur provides incredible shifting speed and precision X-ACTUATION technology eliminates slop and shifting variation ROLLER BEARING CLUTCH technology delivers maximum drivetrain stability With CAGE LOCK technology, wheel removal and installation are easier than ever