Made by The Hickok Electrical Instrument Company Company, Cleveland, Ohio, probably in the 1930's. Model 47X AC Voltmeter. Has some scratched in writing on the face, see pictures. Mount diameter is 2-3/4 (housing OD) and face diameter is 3-1/4 inches. Untested. If not used for testing, think about your next industrial project, rat rod car project, or office and bar decor! I have other vintage meters listed, so take a look! I will combine shipping.