The Straight Head Cable HCST is about 5 feet long and has a male end that plugs towards the Power Pack and a female end that matches with the male plugs on the Flash Heads.
This is a suitable way to extend the Head's built-in cable by an extra five feet or to use a five foot cable directly to the male plug on the Signature Series Heads.
This is a super simple way to extend the Flashtube only into very small spaces and have any amount of power that you want from the bare bulb without the bulky Flash Head body that can be hidden up to about five feet away.
The HFTX Cable plugs into the flashtube socket and has a female flashtube socket at the small end for the actual flashtube to use. It can fit with Modeling Heads but does not extend or use the modeling bulb at all.