Check the listing for details. DY28 Dual Hole Car Spark Plug Tester 12V Gasoline Ignition Plug Diagnostic Tool. Condition: New. Listed at 32.99 USD. DUOYI DY28 Dual Hole Car Spark Plug Tester 12V Gasoline Ignition Plug Diagnostic ToolThe Dual Plug Car Spark Plug Tester is a 12V Gasoline Ignition Plug Diagnostic Tool designed for use in automobile ignition systems. In this system, the high-voltage ignition coil produces a powerful spark which is channeled by the spark plug into the engine cylinder. The spark generated between the spark plug electrodes ignites the fuel mixture. This tester is capable of identifying the efficiency of spark plugs based on the strength of the spark they produce, ensuring optimal performance of the ignition system. This spark plug tester offers a convenient and efficient way to test the quality of spark plugs in gasoline vehicles. With simultaneous dual-hole testing, you can compare the intensity of the test sparks to accurately assess spark plug quality, saving time and ensuring proper functionality. The adjustable working frequency (500-6000rpm) can be easily controlled via a knob, making it suitable for various engine types. Designed for 12V gasoline vehicles, this tester features a high-voltage indicator light for easy monitoring of the testing process. Crafted from durable ABS material, it is moisture-proof, heat-resistant, and impact-resistant for a longer service life. The protective cover enhances safety during testing and allows operators to visually observe the results. Please note that this tester is not suitable for use with lawn mowers and chainsaws. For compatibility concerns, feel free to contact us before making a purchase.Upgraded Spark Plug Tester:*Tests spark plug performance and ignition strength. *Tests the full range of spark plugs for 12V gasoline vehicles. Suitable for spark plugs with nut diameter of 14MM and 16MM. Fit for BMW/Mercedes/Audi/Porsche/German luxury cars, etc.wider range of applications.Dual-hole Comparison Test: By comparing the spark intensity of the new and old spark plugs, you can judge the performance and ignition intensity of the old spark plugs and decide whether to replace them.Adjustable Test Hole Height:The height of the test hole can be adjusted toaccommodate cup-shaped spark plugs.Adjustable Test Frequengy: Spark plug tester can adjust the working frequency, you can adjust it between 0-6000rpm/per minute, the higher the setting frequency, the stronger the spark strength.Protective Cover Design:Designed with a safety protection cover to avoid being injured by accidental contact during the test.Plug-And-Play: Spark plug tester is easy to operate and can be used by just connecting the adapter, making it easy for even novice operators to use.Operation Steps:1. Insert the spark plug into the test hole.2. Connect the power.3. Rotate the switch clockwise.4. Then through the protective cover to observe the spark plug test state.