Wide application: In addition, the standard plug wire head can be unscrewed, so the tester can be used on small engines and some motorcycles. This is a must-have tool for professional workshops and auto repair shops, as well as a great helper for home vehicle repairs. Wide application: In addition, the standard plug wire head can be unscrewed, so the tester can be used on small engines and some motorcycles. This is a must-have tool for professional workshops and auto repair shops, as well as a great helper for home vehicle repairs. Wide application: In addition, the standard plug wire head can be unscrewed, so the tester can be used on small engines and some motorcycles. This is a must-have tool for professional workshops and auto repair shops, as well as a great helper for home vehicle repairs. Wide application: In addition, the standard plug wire head can be unscrewed, so the tester can be used on small engines and some motorcycles. This is a must-have tool for professional workshops and auto repair shops, as well as a great helper for home vehicle repairs. ADJUSTABLE: The round knob makes it easy to adjust the gap, and it comes with a shielding clip to hold it securely to the floor. He can intuitively and easily understand how an ignition coil works. Key Features: The engine spark tester is an essential diagnostic tool for any engine with spark plugs, allowing you to quickly and easily diagnose ignition/outboard engine problems or fuel supply system malfunctions.