Waytek's new Battery Selector/Disconnect Switch is designed for vehicles using two batteries, and allows current to be carried by either one of the batteries or by both batteries simultaneously, or cuts off all power. It functions with alternators or generators and protects against electrical fire, battery drain, tampering, and theft. High amp capacity rated at 500A intermittent, 310A continuous, 6-36 volts DC, the switch is vapor proof, waterproof, dust proof, and corrosion resistant. It's ideal for emergency and rescue vehicles.