1. Lighting function and polarity indication: The cable tester can illuminate the test area when testing in the dark. Additionally, you can attach the large alligator clip to either a negative or positive ground—green light indicates positive polarity, while red light indicates negative polarity. 2. SHARP PRACTICAL: Equipped with a sharp, superhard steel probe for piercing wires to inspect electrical circuits. The long probe and large alligator clip are ideal for hardtoreach places. 3. Powerful Functions: Capable of detecting fuses, identifying positive and negative power supplies in electrical appliances, checking battery power, testing LAN circuits, distinguishing between real/virtual current and poor grounding, reading fault codes, and detecting Hall sensor and line shortcircuit errors. 4. DESIGNED FOR: This automotive circuit test pin tester is suitable for detecting lowvoltage cables and circuits (624V) in cars, trucks, boats, RVs, trailers, motorcycles, and more.