A dedicated 1 x rear derailleur and weight is 261 g exact actuation for fast and accurate shifts using srams 1 1 actuation ratio shifter cable travel derailleur movement is 10 and 11 speed compatible x sync pulley features a 12 tooth design that helps control the chains lateral movement x horizon straight parallelogram design limits all movement to the horizontal axis which makes ghost shifting impossible while also reducing shift force roller bearing clutch one way roller clutch controls