Description [Wide Application]: The inline spark plug tester is a must have diagnostic tool for any engine with a spark plug, it fit for all internal and external combustion engines, cars, trucks, motorcycles, lawnmowers, chainsaws, trimmers, snow-blowers, generators engines etc. Spark plug tester apply to any household, business, mechanic, industrial and commercial spark plug use in engine. [Premium Materials]: The probe of this spark tester is made of high quality plated shaft, the optical housing is made of environmental friendly acetate plastic, and rubber straight jacket and cable. High quality materials are resistant to rust and corrosion, even in high and low temperature environments. [Easy to Use]: Easily determine which cylinder is causing issues with this spark plug test light; Simply connect the spark detector spark plug tool between the spark plug and the plug wire then start the engine; If sparks are being sent, the in line spark tester will mirror the spark by lighting up; If checking a no start condition, have a friend crank the engine so you can watch for indications of a spark. [Light Indication]: The spark plug engine ignition test kit is equipped with a high intensity neon bulb inside, which makes it easy to know if the ignition wires are intact by flashing. By light indicator shows of spark plug engine ignition tester to determine which cylinder is causing the issue and track down the exact cause. [Excellent Customer Service]: We are dedicated to researching in-car products to improve driving safety and comfort, bringing you a pleasant driving experience. Should you have any questions, please do not hesitate to let us know. We are ready to help you