Up to 600A 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. Voltage Rating: 32 VDC Max