Dual Hole Test:Spark plug tester testing is used to test the performance and ignition strength of spark plugs. Dual hole testing function allows for quick and accurate testing of the performance of spark plugs by placing a new spark plug and a spark plug separately in the testing hole. It can truly the working conditions of the engine. The measurement process is more effective and the measurement results are more accurate. Adjustable Working Frequency:Spark Plug Tester working frequency of car is 0-6000 rpm. You can adjust it according by rotating the switch, which is very convenient. The higher the frequency, the stronger the spark intensity. High Quality and Applicability:Car spark plug tester is made of high-quality thermoplastic polymer structural material (ABS), good heat resistance and impact resistance, and can extend its service life. It can be used to test 12V gasoline vehicles with a diameter of 12mm and is compatible with 99% of crankshaft engines and motorcycle spark plugs on the market. Plug and Play:Spark plug tester is very simple. Spark plug to be tested needs to be placed in the test hole, and then connected to the power supply to start the test. It also has a power indicator light and two high-voltage signal indicators, which can help you observe the test more intuitively. NOTE:It is not suitable for testing short plugs on lawn mowers, chainsaws, or most small motors. name: ST100 Car Spark Plug Tester Power supply: 100-240V Speed: 0-6000rpm/min Double hole: 13MM Voltage:12V Voltage:AC100-240V Plug Type:US Plug,it applies to Canada, India,Mexico, Thailand, the , the Philippines,Taiwan and so on. Colour:As Shown Material:Plastic + Metal Package Contents: 1 x ST100 Car Spark Plug Tester (Not Included Spark Plug) 1 US Plug 1 x EU Plug Adaptor 2 x limit gaskets Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.