1、LOCATE OPEN CIRCUITS: It immediately detects and alerts you when a circuit is open. You can quickly and easily locate short circuits, open circuits, broken wires, current leaks and even trace wires. Transmitter and receiver indicators show open or short circuit conditions. 2、CHECK FOR SHORT CIRCUITS: You can also spot intermittent circuit problems by bending wires or connectors and tuning in to changes in the receiver's tone. A 7 inch flexible probe helps to reach wires in crowded areas. 3、APPLICABLE POWER SUPPLY: It is suitable for a variety of circuits with voltages between 6‑42 volts DC, such as cars, trucks, tractors, boats, RVs, etc. 4、SAFETY PROTECTION, PORTABLE DESIGN: Features internal protection against power surges and overloads. Built in buzzer to indicate open or short circuit conditions by sound. Comes with a storage bag for easy portability. 5、QUICK DIAGNOSIS: This tester can be used to determine the continuity of cables or wires and diagnose breakpoints, helps to find faults in car circuits, effectively saving time and making your repairs faster.