Trailer connectors in Australia

A number of standards prevail in Australia and New Zealand for trailer connectors, the electrical connectors between vehicles and the trailers they tow that provide a means of control trailer lamps, and in one case, trailer brakes, and also sometimes, manufacturer-specific non-standard functions. The Australian market generally uses its own version of the European connectors, as well as its uniquely own contacts.

Source: Wikipedia — Trailer connectors in Australia (CC BY-SA 4.0)