American-made Ronk products are designed to increase efficiency, stabilize power usage, and let you walk away at night knowing that all systems are operating smoothly. Founded in 1950, Ronk is a market leader in manufacturing phase converters, power factor correction capacitors, stray voltage isolators, double-throw switches, automatic transfer switches and outdoor equipment enclosures. Located in Nokomis, Illinois, Ronk provides contract manufacturing services and operates NanO2, an advanced aeration technology company.