Blue Sea Systems 3002 HD-Series Heavy Duty 4 Position Selector Battery Switch

Up to 500A continuous rating for large diesel engines. One-piece tin-plated copper stud design never loosens over time. Terminal studs accept 1/2" or M12 ring terminals. Ignition protected and UL Listed. Selector features make-before-break contact design. AFD ( Alternator Field Disconnect models allow switching while running the engine without damaging the alternator.