1. It is one of the four main types of wires. 2. It receives and gives spark to NSCN/PSCN 3. PTCT and NTCT always receive sparks from NSCN and always give power to PSCN (From PSCN they only transfer under the certain temperature level) PTCT, NTCT, INWR and METL transfer only to themselves and certain silicons(I mentioned them before)