SRAM, Force1 Type 3.0, Rear derailleur, 11sp., Long, BlackEXACT ACTUATION for fast and accurate shifts using SRAMs 1: 1 actuation ratio (shifter cable travel: derailleur movement) X SYNC pulley features a 12 tooth design that helps control the chains lateral movement ROLLER BEARING CLUTCHs 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 shift force