This tool is used to protect the on-board electronics from voltage peaks that can occur, for example, when using energy from an external source for a quick start (battery connected to another vehicle or booster).
The use of this appliance is simple and quick.
Connect the two clamps to the battery poles.
The light indicates the working voltage (12V / 24V)
The buzzer sound indicates the presence of voltage spikes that the surge protector is dispelling.