This PC Sync cable, which plugs into either of the Camera/Flash ports on the Camera Axe, lets you attach a flash to the Camera Axe for high speed photography. This only works with flashes that have a PC Sync cable port. Photos that require near instant reaction times like milk droplets, breaking glass, or popping balloons can’t rely on the camera shutter. Camera shutters have a shutter lag that varies depending on the camera model, but 50 milliseconds is a pretty fast shutter reaction and in these types of photos 50 milliseconds is just too long. The solution is to set the camera for a long exposure (5 seconds) in a dark room and have the Camera Axe trigger a flash. Flash lag time is much much less than one millisecond so it can catch these events with sub millisecond response times.
Using a high voltage flash unit will damage the Camera Axe. Here is a list of safe flashes (flashes that are EOS safe are also Camera Axe safe).