Features & Description: NEW Circuit Tester for 6V / 12V DC Systems Long Probe Continuity Tester. High quality circuit tester for 6V and 12V electrical systems can be used to detect power, ground and find shorts and breaks in wires. Handle brightly illuminates if circuit is good. Quickly check automotive headlights, taillights, turn signal circuits, faulty sockets, connections, fuses, broken wires and more. .