The Pollak 51-902EP Master Disconnect Switch works on trucks, RVs, travel trailers, ATVs, marine vehicles, boats, and other machines that use a 12V battery. Two studs on the bottom of the switch let you connect one to the battery and the other to the starter. Once in place, simply turn the lever and your battery and connected machinery will no longer have a connecting current. This will help prevent battery drain, electrical fires, and other potential issues that can occur when your battery is not in use. The battery switch can also help you avoid theft. If your battery and starter are not connected, then there will be no way to start your device. It's one of the best theft deterrent options available. The Pollak Battery Disconnect Switch is made of heavy-duty, non-corrosive materials that are long-lasting and waterproof. An easy-to-read faceplate lets you easily change the setting. Helps prevent battery drain, electrical fires, & other potential issues Disconnect your vehicle from battery & starter to help prevent theft Made of heavy-duty, non-corrosive materials