The CLEAN X3 rear trial hub belongs to the family of thru axle hubs. You will find these hubs on the new CLEAN K1 carbon bikes and also the CLEAN X3 World Cup. The hub has a new larger pitch of 120mm and is thus compatible with the CLEAN K1 and CLEAN X3 frames. Disc attachment with standard 6 bolts. Hub comes with 12mm thru axle.