SRAM GX Rear Derailleur 12sThe SRAM GX Eagle 12 Speed Rear Derailleur harmoniously shifts through all 12 gears of your Eagle drivetrain without noisy chain slap or annoying ghost shifts holding you back on the trail. Borrowing shifting technologies from its pricier XO1 sibling, the GX Eagle 12 Speed Rear Derailleur is a low cost alternative that retains SRAM's X Sync 14 tooth lower pulley system, X Horizon parallelogram design, and Type 3 Roller Bearing Clutch. Best of all,