
I was wondering if anyone could help me on this one

Im guess that the Black wire goes to earth, and the red goes to a switched ignition live.
However what is the other plug thing for?
Also the sockets for the headsets look like this:


Now if each plug was for a headset, how does it work, as surely it should have 2 sockets per Headset, one for microphone and one for Headset. if they require special headset, then any idea where to get some cheapily?
Help much appreciated.