[mazdaparts]

It doesn't really matter, but most rc wire is silicone insulated with a lot of thin strands of wire to keep it very flexible opposed to copper wire which may have a plastic thinner insulator and fewer larger strands. Either will work but when extending the esc wires you want to get the same wire if you can. It is possible to open up the esc and de-solder the wires and add new longer wires. You can order it from tower hobbies or any hobby shop should have it in stock.