Adjustable Working Frequency : Customize the spark plug tester to your specific needs with variable frequency. High Voltage Indicator : Easily monitor the voltage level for accurate spark plug evaluation. Plug-and-Play Convenience : Quick setup and easy-to-use design for immediate diagnostics. Durable Quality : Constructed with impact-resistant and heat-proof ABS material for long-lasting performance. Lifelong Maintenance : Peace of mind with comprehensive maintenance services and support. Unleash the power of precision with our Adjustable Working Frequency Spark Tester. Designed to meet the demands of automotive enthusiasts and professionals alike, this tester boasts a user-friendly interface and reliable construction. Perfect for diagnosing spark plugs in 12V gasoline engines, it ensures your vehicle runs at peak performance with every turn of the key.