Sram Accessory Rear Derailleur Force1 Long Cage 11-SpeedFeatures EXACT ACTUATION for fast and accurate shifts using SRAM's 1: 1 actuation ratio (shifter cable travel: derailleur movement) X SYNC pulley features a 12 tooth design that helps control the chain's lateral movement ROLLER BEARING CLUTCH's one way roller clutch controls chain tension for consistent shifting X Horizon straight parallelogram design limits all movement to the horizontal axis, which makes ghost shifting impossible while also reducing