Itís just a standard hella plug, I purchased a few of them when I had my Triumph.
Itís primary function is for my Battery Optimiser, itís wired directly to the battery, it could also be used for anything, heated clothing, powering cameras etc.
To install I removed the seat, rear rack, moved the main fuse and some of the wiring out of the way, drilling an 18mm hole using a cone drill and made a wiring harness. Job done. Works a treat and looks like it should be there.