- Effortless System Checks: This test pen features a wide detection range and a 13.5 ft cable, making it ideal for quickly diagnosing various electrical systems without hassle. - Versatile Applications: Use the pen to identify polarity, assess motor and lamp functionality, test conductivity, and effectively trace short circuits. It's an essential tool for accurate vehicle troubleshooting. - Enhanced Safety: Equipped with built-in short circuit protection, this tester ensures a safe experience while quickly detecting poor ground connections, making your testing process reliable and secure. - Simple Operation: Attach the Voltage Tester Pen to the car's battery, then easily switch the power on and off by shaking it forward or backward. This allows for straightforward polarity checks from the battery to the tip. - Practical Use Cases: - Identify battery polarity to ensure proper connections before installation. - Test the functionality of headlights and taillights to ensure they are operational. - Trace electrical issues in vehicles to quickly locate and resolve short circuits. This product combines functionality and safety, making it a must-have for anyone working with electrical systems.