Just for reference on this old post. The Copper leads in the connectors is 26awg and not 18 (you could probably use 28awg which should handle the amps and get thru close spaces easiest) and but certainly not 18awg. I have made my own small contact switches with the ECU's from big climbing switches from DI2 and the wires are again, not 18awg. That post will have people purchasing the wrong too large size wire for their extensions. Also, it is really easy (if you are a electronics or computer geek) to make your own extensions with the correct size wire. Just find advice on youtube about splicing small electronic wires.