OPEN CIRCUIT LOCATIONPowered by 2 * 9V batteries. It detects and alerts you immediately when a circuit is open. You can quickly and easily locate shorts, open connections, broken wires, current leaks, and even trace wires. Transmitter and receiver LEDs indicate open or short circuit conditions. CHECK FOR SHORT CIRCUIT You can also find intermittent circuit problems by bending wires or connectors and listening for a change in receiver tone, the 7 inch flexible probe helps reach wires in congested places. SUITABLE FOR DC 6~42 Volt CIRCUIT POWERIt will work on all kinds of circuits with voltages between 6 and 42 volts DC. (such as those found in automobiles, trucks, tractors, boats, recreational vehicles, etc.) With its wide operating voltage range.). OPERATION VIDEO Check out our video on the left side, internally protected against overvoltage and overload. Built-in Buzzer Sound Show under open circuit or short circuit condition, comes with a storage bag, easy to carry. QUICK AND EASY DIAGNOSISJudge the continuity of cables or wires and diagnose the breakpoint. Saves time, making your repairs faster, makes it easier to find problems. I tried to find a fault in the automatic electrical circuit.