This heavy-duty 12V 200A battery isolator relay is an essential component for vehicles requiring reliable dual battery management. Designed to handle high current loads, this universal 4-pin relay ensures your primary battery remains protected while powering auxiliary systems or starting your engine. The robust construction features copper terminals and a durable housing that withstands the demanding conditions of automotive, truck, RV, and marine applications. With its 200-amp capacity, this relay efficiently manages power distribution between batteries, preventing drain on your main battery when the engine is off. The compact design measures approximately 2 inches in length and 1.2 inches in width, making it easy to install in confined engine compartments or electrical panels. The clearly marked pin configuration (30, 86, 85, 87) simplifies wiring for both professional mechanics and DIY enthusiasts. Whether you're upgrading your vehicle's electrical system, installing aftermarket accessories, or building a dual battery setup for off-road adventures, this reliable switch relay delivers consistent performance you can count on.