Over current protective device: automatic self-resetting when over current

 Up to 50 Amp

 Accept 4 AWG power cable

Sometimes people will wire to wrong electrode when using emergency cable. With this device connected to the cable, the LED will on when the current goes normal. When wiring to wrong electrode (positive connect to negative, the LED will off, and no current flow from car to car. This can protect cars from overloaded circuit.