1When the circuit is disconnected, it detects and alerts immediately, allowing you to quickly and easily find shorts, disconnects, broken wires, power leaks and even trace cables. 2You may also experience intermittent circuit problems by bending the cable or connector and listening for changes in the receiver's tonality. It allows you to track or determine the location of the problem. It also uses the direction indicator to display the address briefly, eliminating the need for doubt. 3With a wide range of working voltage, this professional tool will work on all kinds of circuits with voltages between 6V and 42V DC. Suitable for car, truck, tractor, ship, SUV, etc. 4The tester can quickly and easily locate short circuits, saving your times and increasing your income. It can judge continuity of the cable or wire, track the cables or wires, and diagnose the break point. 5Receive the tonality signal on the cables or wires (telephone line), identify the state in the working telephone line (clear, ring, busy) and send a single tonality or a dual alternating tonality to the object cables or wires.1 x Tester (Battery Not Included)1 x Bag1 x English User Manual1 x Receiver