Multi-Function Audible Auto Tester For 12 - 24 Volt Systems Voltage Testing Polarity Testing Continuity Testing Ignition Pulse Frequency Peak Detection Ensure the optimal functioning of your vehicle's electrical system with this versatile tester. It's designed for 12 - 24 volt systems and can easily test voltage, polarity, continuity, ignition pulse frequency, and peak detection. Don't leave your car's performance to chance - trust in the reliability and precision of this multi-function tool.