Its a weird one, There is several slots on the one side of the box unit for the extra gauges we presume and on the other side is some more wires with the connectors on them and another connector with just a black and red wire (we take it this is the wires needed to power the gauge) But what plugs into it and where it goes we do not know Gutted I sold it now, been looking at some nice GT's to buy instead of a Civic now