Automotive Two Spark Plug Tester , Spark Plug Tester , 12V Spark Plug Tester For Test Display Characteristic: Easy to use, plug and play, economical and useful tool. Two test holes, you can test two spark plugs meanwhile. More intuitive display of spark plug status. The tester is used to test the properties of spark plugs and ignition strength. Scope of application: 12V gasoline vehicles, automotive spark plugs Specification: Item Type: Spark Plug Tester Material: ABS metal Colour: black Power Supply: Input 100-240V AC / Output 12V 1A DC Size: about 145*85*60mm (There may be 1 to 2mm deviation due to manual measurement). Application: 12V petrol spark plug Product Feature: Spark plug tester: The two-hole automotive tester has two test holes and can test two spark plugs at the same time. If you suspect one of them is not working properly, you can compare and test it to make an accurate assessment. What is the role of the spark plug? The spark plug's job is to introduce tens of thousands of volts of high-voltage current into the combustion chamber and create electrical sparks to ignite the mixture. The spark plug works in conjunction with the ignition and fuel supply systems to ensure normal engine operation, which is critical to engine performance. Spark plugs are an everyday operating element in cars. As the core of the car engine, they can almost directly determine the car's performance. Therefore, you should always check the spark plug in your car. Turn off the power before placing the spark plug The spark plug tester is a high voltage detector, so do not touch the spark plug with your hand during operation to avoid danger. Automotive spark plug tester manual: put the spark plug in hole 1 or 2 of the tester; if you want to compare the new spark plug with the old one, put the new spark plug in hole 1 and the old one in hole 2. connect to power turn the key switch clockwise to turn on the tester, the indicator will be on, the tester now runs at 1000 rpm. Turn the switch clockwise again to adjust the operating frequency from 1000 rpm to 5000 rpm. The higher the frequency, the greater the spark strength. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.