M3 Ball Joint Rod Ends are compatible with the REV DUO System. The Female M3 Ball Joint Rod End (REV-49-1560) can either be paired with its male counterpart to create short linkage arms or with M3 threaded rod and a second female ball joint for longer distances. It should be noted that linkages using threaded rod should only be under tension loading. The Male M3 Ball Joint Rod End (REV-49-1561) can either be paired with its female counterpart to create short linkage arms or threaded into the ends of the 15mm Extrusion.