1. Wide Application: The Car Electric Circuit Tester is designed for use with 6V to 24V DC automotive electrical systems, making it an essential tool for diagnosing issues in cars, trucks, boats, trailers, and motorcycles. Its versatility ensures that you can tackle a wide range of vehicles effectively 2. Overload Protection Feature: This Automotive Electrical System Tester is equipped with an overload protection device that automatically trips when current exceeds 8A, preventing damage and ensuring your while using the tester. This feature adds peace of mind during diagnostics 3. Polarity and Continuity Testing: Easily determine uncertain polarity in vehicles with the multifunctional drive test pen. The LED indicator shows red for positive and green for negative, while also allowing for continuity testing of switches, relays, diodes, fuses, and circuits, streamlining your troubleshooting process 4. LED Indicator & Buzzer Alerts: The built-in LED light and buzzer provide dual warnings, giving clear visual and audible signals for easy understanding of test results. When the current exceeds 7A, the circuit tester will disconnect automatically, ensuring you stay informed about potential faults in your vehicle's electrical components