This circuit tester is great for checking issues in vehicle circuits, handling functions like continuity testing, polarity checks, jumper operations, and short circuit tracking with ease. To use it, attach the red clip to the battery’s positive terminal and the black clip to the negative. When the probe tip touches the positive terminal (+), the LED glows red; when it touches the negative (-), it glows green. For a continuity test, connect the tester properly, then attach the auxiliary cable to one side of the circuit and the probe tip to the other. If the circuit is complete, the LED will glow green; if not, it stays off. With its sensitive probes and clips, this tester delivers quick, accurate results, and the LED indicator and sound signal make the testing process even clearer.