This dual battery switch is a four-position selector (OFF / Battery 1 / Battery 2 / BOTH) designed to manage two battery banks on your boat. It enables you to alternate between batteries or combine them for dual power, as well as completely disconnect both when your vessel is not in use. Built for 12V and 24V systems (compatible up to 32V), this switch carries 100A continuously and handles up to 300A intermittently, providing reliable power transfer for engine starting and onboard electronics. Its construction features a durable bakelite/ABS plastic housing with corrosion-resistant brass terminals, ensuring longevity in the marine environment. A safety clip-on lock on the rotary knob prevents accidental switching and meets CE standards for marine electrical safety. The switch’s compact design (approximately 69×69×74 mm) allows easy installation on a control panel or battery compartment. Use the “BOTH” setting to parallel batteries for increased power (for example, during engine start), or isolate each battery to dedicate one to engine and one to house loads. When set to “OFF”, it completely disconnects the electrical system to prevent battery drain and enhance safety during maintenance. This product is an Osculati/Eval battery selector, engineered for safe and efficient battery management, giving you flexible control over two batteries from a single, easy-to-operate switch.