The Apex XPLR derailleur hits the sweet spot of smooth jumps over a big gear range, all with unmatched chain security and the simplicity of a 1x drivetrainX-Horizon straight parallelogram design limits all movement to the horizontal axis, which makes ghost shifting impossible while also reducing shift forceWorks with 12-speed mechanical Apex and Eagle shiftersClutch controls chain tension for consistent shiftingCompatible with cassettes with 44T large cogsUse with FlatTop chainsApex XPLR1244Long1to1BLKUPC/EAN/GTIN: 710845887512