- Widely compatible: The ignition system detector tests the performance and ignition strength of spark plugs for all internal combustion engines and common equipment, including trimmers, snow blowers, generators, motorbikes, cars, trucks, lawnmowers, and chainsaws. - Excellent material: Made of high-quality plastic and alloy, this spark plug tester is high temperature resistant, well made, and durable. - Quick diagnosis: Easily determine whether the ignition system is working properly and troubleshoot problems, quickly locating faulty points and bad circuits to avoid dangerous situations such as burnt ignition coils and fires. - Easy to use: Includes crocodile clips for simple connection to the spark plug and spark plug wire. During testing, a purple-blue, two-centimeter-long straight line indicates a normal spark plug, while a defective ignition coil appears red or curved. - Use scenarios: Ideal for car maintenance and repair, on lawncare equipment (mowers, trimmers, chainsaws), and for testing generators or snow blowers in off-season or service work.