1. MULTY FUNCTION: automotive short open repair tester tool is used to detect and alert you immediately where a circuit is open. You can quickly and easily locate short circuits, open connections, broken wires, current leaks and even trace wires. Also can receive the tone signal on the cables or wires(telephone line), identify the state in the working telephone line 2. WIDE APPLICATION: This short and open finder circuit tester is suitable for use in the generation of vehicles with mixed or single 42 Volt systems, and can operate at a DC voltage of 6 to 42 volts. Such as those found in automobiles, trucks, tractors, boats, RVs, etc...With its wide working voltage range 3. EASY TO OPERATE: The curved receiving probe can better detect cables in crowded and narrow environments and improve the detection efficiency. Adjustable sensitivity helps to achieve more accurate detection results 4. INTERNALI PROTECTION FUNCTION: The automotive short and open finder circuit has internal protection function to prevent surge and overload. Transmitter and receiver LEDs display open circuit or short circuit status 5. BUZZER ALARM: When the circuit breakpoint is detected, the receiver will give an alarm. And the closer the probe is to the power failure, the faster the sound frequency and the higher the volume, which can help you quickly determine the circuit problem 6. HEADPHONE CONNECTION: 3.5mm headphone jack monitor detection, even in a noisy environment, it can perform cable short-circuit point inspection, cable tracking and cable identification operations, so as to prevent noise from affecting the judgment result