Anti-lost Probe Cover & Premium Longer Spring Wire Sharp stainless steel probe can pierce wires and reach tight spaces. The anti-lost silica gel needle cover is built into the spring wire, so you won’t lose it during testing or storage. 140 inch PU spring wire provides flexibility, is lighter and more durable than ordinary cables, and is convenient for use and storage. Includes a large-size alligator clip for easy one-handed operation. Light Indication Bidirectional Voltage Testing and Two Buzzing Sounds This is a bidirectional volt tester. Attach the alligator clamp to either negative ground or positive pole. The circuit board has two LEDs for polarity indication: red for positive, green for negative. It emits one buzz for positive voltage and a double buzz for negative. 3-72 V Wider Testing Range Professional 3-72V DC voltage testing range, wider than typical 48/60V auto testers. Ideal for checking vehicle electrical circuits, headlights, taillights, turn signals, faulty sockets, and fuse connections. Also suitable for testing other 3-72V DC wirings and circuits. Computer Safe Accurate LED Digital Reading Clear, bright LED voltage display with 0.1V resolution for accurate readouts. Visible day or night. Lower current draw than traditional bulb test lights, making it safer for automotive computer boards and reducing the risk of damage. Practical use scenarios - Inspecting car lighting circuits (headlights, taillights, turn signals) to verify voltage and polarity. - Troubleshooting faulty sockets, fuse connections, and wiring harnesses in cars, trucks, motorcycles, or trailers. - Testing other 3-72V DC circuits in workshops or industrial equipment to confirm proper voltage and polarity. This device provides a robust combination of long reach, reliable polarity indication, broad voltage range, and computer-safe digital readouts for accurate, straightforward diagnostics.