This Attwood Battery Switch makes it easy to control when a battery is providing power so you can ensure it doesn't drain accidently between uses. It is for use with a single battery, 12-50-volts DC. This compact, heavy-duty battery switch features an ergonomic, removable control knob to ensure you control the battery's power and to prevent theft. Attwood Corporation has been an award-winning leader in engineering, testing, and manufacturing of the highest quality marine products for over 100 years. We deliver safe and reliable lighting, fuel systems, water systems, seating & pedestals, swim ladders, custom upholstery, and general marine accessories that are easy to install and meet regulatory compliance.