Inter Michael got it pretty well described. Dont do what I did in ignorance which was to undo one of the tied off elastics (tied off because not in use), and then promptly let it go to watch it hurtle into the front beam not to be seen again. At this point you find the downloadable Inter 20 manual is useless! Then you have to find someone who knows how to reconstruct the system to come over and help you fix it. You can either use the system to stow any loose line from the main downhaul system, or the mast rotator control system. Perhaps it could do both at the same time if you were clever with lengths of line?
Regards
Chris