VDIAGTOOL 6-42V Automotive Circuit Tester 1. Power supply: 9V battery (not included) 2. Compatible with a variety of circuits between 6-42V DC, including cars, trucks, tractors, boats, RVs, etc., with a wide operating voltage range for a variety of applications 3. Equipped with an adjustable 7-inch flexible probe, providing flexibility to reach difficult areas 4. The receiver's probe is constructed of rolled steel and can be bent as needed to access wires in crowded or challenging spaces 5. Depending on the characteristics of the circuit and the sensitivity setting, the probe will detect signals from wires in different locations 6. Place the receiver's probe tip (black cap) vertically (90 degrees) above or below the wire being traced 7. Easy to use, simply place the transmitter in series with the circuit or wire being tested (e.g.: in place of a blown fuse, through a connector, in series with an open wire, light bulb socket, etc.) and use the tracer's flexible probe to scan the circuit or wire to find the fault point 8. Allows you to identify intermittent circuit problems by bending the wire or connector and listening for changes in the receiver's tone 9. Open wire detector instantly detects and alerts you to open circuits, easily locates shorts, broken wires, disconnects, current leakage and traces wires; sends and receives LED indications for open or short circuit conditions 10. Powered by 2 9V batteries, easily locates breaker points, open connections, broken wires, current leakage with tone changes, and even traces wires or cables without damaging insulation