- Upgraded unique design: Sharp stainless steel probe can pierce insulation and reach tight areas. The integrated structure of the probe protection cover adds a needle guard to prevent stab wounds, and the guard cannot be lost. Compact and easy to carry for use anywhere. - Digital LED and buzzer bidirectional indication: The alligator clip and probe can connect to the positive and negative poles bidirectionally. When connected to the positive pole, the unit pulses once with a red light on. When connected to the negative pole, it beeps twice with a green light. The digital readout is not backlit, but remains clear and visible under any light conditions. - Computer-safe, sturdy and flexible: Built-in circuit board chip makes the tester safer and more durable than traditional test lights, helping protect car computer boards from damage. The spring wire can be freely stretched up to 140 inches (about 3.56 meters) for a wide measuring area. The anti-bending tail wire design reduces the risk of poor contact. - 3-72V wider voltage range: The device supports normal digital display within 3-72V; voltages below 3V show "---" and voltages above 72V display blank. The maximum voltage measured with this technology is upgraded to 60V, and the reading resolution is 0.1V with an accuracy of ±0.2V, providing professional-level precision. - Practical applications: Automotive electrical diagnosis such as testing battery and charging circuits, wiring harnesses, and fuses; checking positive/negative polarity in vehicle electrical systems; bench testing 12V-24V DC circuits and small electronic modules in workshops or DIY projects.