Test spark plug performance and ignition intensity The spark plug tester is suitable for gasoline vehicles with spark plugs up to 12V. The tester is used for small engines to test spark plug performance. Spark plug performance is tested by simulating the ignition of a car, to decide whether to replace the spark plug. The inner size of the test hole: 12mm.Plug and Play andamp Double Hole DetectionPut the spark plug into the test hole, cover the protective cover and turn on the power. The automotive spark plug tester detector has a two-hole test function, which can perform two-hole simultaneous testing. By comparing and testing the spark intensity, the spark plug can only work normally if the quality of the spark plug can be accurately judged.With Shock Resistance, Durability and Protective Cover ProtectionThe spark plug tester is made of high quality ABS material, which is characterized by shock resistance and heat resistance. The spark plug tester has a transparent protective cover, and the latest automotive spark tester has a special protective cover design.Adjustable Working Frequency Spark TesterAutomotive spark plug tester adopts wide working frequency adjustment range. By operating the rotary switch, the working frequency between 500 and 6000 rpm can be adjusted. The higher the set frequency, the stronger the spark intensity. It can be adjusted as needed, saving time and efficiency, more accurate.Easy to use and intuitive display The spark plug is easy to operate, just test the new spark plug and the spark plug in the test hole, you can quickly and accurately test the performance of the spark plug, and has a power/high voltage indicator, which can help you to visually observe through the protective cover the condition of the spark plug.