This product detects an open circuit and alerts you immediately. You can find shorts, opens, broken wires, current leaks and even traces quickly and easily. You can also spot intermittent circuit problems by bending wires or connectors and listening for changes in the receiver's tone. Allows you to perform general tracking or pinpoint the location of the problem. Its directional indicator also shows the direction of the short circuit, taking the guesswork out of it. ?The instrument includes a transmitter and a receiver ?Transmitter and receiver LEDs indicate open or short circuit conditions ?Locate short circuits quickly and easily ?Determine continuity of cables or wires ?Trace cables or wires and diagnose break points ?Receive tone signal via cable or wire (telephone line) ?Identify status in work phone lines (clear, ringing, busy) ?Sends a single solid tone or dual alternating tones to an object cable or wire ?Trace wires even inside wiring harnesses, conduits, panels, under carpets, upholstery, and more ?Easy to use. Simply place the transmitter in series with the circuit or wire under test (ie: in place of a blown fuse, through a connector, in series with an open wire, light bulb socket, etc.) and scan the circuit with the tracer flexible probe /wire to find the fault point ?For new generation vehicles with hybrid or single 42V systems ?Operates on DC voltages from 6V to 42V ?Internal protection against power surges and overloads ?7" Flexible Probe Accesses Wires in Congested Areas Specification: ?Working temperature: 58?? ?Applicable voltage: DC voltage 6V-42V ?Applicable models: various models ?Power supply: two 9V batteries (not included) ?Width: 4cm ?Material type: Coil ?Height: 15inches ?Length: 17cm How to Use the Probe? ?The receiver's probe is made of coiled steel and can be bent as needed to access wires in difficult or difficult areas. Depending on the circuit characteristics and sensitivity settings, the probe will pick up the wire's signal at a range of locations. However, for optimal range, the receiver's probe tip (black cap) should be positioned perpendicular (90??) to the wire being traced, either above or below the wire. Package included: ?1 x Receiver ?1 x Sender ?1 x English User Manual ?1 x Storage Bag ?Other things not included