The electronic Startguard Surge welding protector is ideal for use when welding on your vehicle or plant, no need to remove or disconect your battery anymore! Just connect the large insulated crocodile clips to positive and negative battery terminals. The Protector electonically stops "spiking" through the vehicles intricate circuitry and the LED Status indicator shows correct connection. The indicator light shows green when the clamps are properly attached, If the red light shows, work must not commence as the unit is not protecting your vehicle or plant. Now what could be easier. For use on 12vdc or 24vdc systems, the continuous usage rating is 35vdc and has a maximum voltage of 44vdc and must not ever be exceeded.