1.Wide Application & Overload Protection The power circuit probe tester is made of ABS material, which is moisture-proof, high-temperature resistant and has a longer life. It is suitable for diagnosis of all 6V to 24V automotive electrical systems and can work well on cars, trucks, boats, trailers, and motorcycles. The tester also has an overload protection device. When the current exceeds 8A, the circuit breaker inside the device will automatically trip and give out a buzzer prompt 2.Polarity Test & Continuity Test The power circuit probe tester can be used to test uncertain polarity in vehicles. When the dc circuit tester touches the positive pole, the LED should be red; when it touches the negative pole, the LED should be GREEN. The power circuit probe tester is also used to check the continuity of switches, relays, diodes, fuses, and circuits 3.LED Indicator& Buzzer Dual Warning In order to let you understand more intuitively and clearly understand the grounding of the components, the power circuit probe tester comes with an LED indicator and a buzzer. The test light can perform a quick self-test to ensure your tool is in good condition. When the current exceeds 7A, the circuit tester automotive will disconnect the current automatically and give you a buzzer prompt, reminding you whether the tested component is faulty 4.Tracking and Locating Short Circuit: The power circuit probe tester uses advanced high-sensitivity probes to provide you with fast and accurate detection. Using this automotive test light can save a lot of time to troubleshoot the car wiring circuit, to quickly and accurately find the faulty wire and its fault point