Heavy-duty construction and high quality materials - Built with durable, high quality materials to let you reliably test whether your spark plug is functioning correctly. By verifying if the ignition is truly the source of the problem, you can save time and money. High quality spark plug tester for reliable diagnostics - This tester attaches to spark plug connections and diagnoses spark events and misfires, along with defective contact points, bad cables, and more. It is designed to withstand regular diagnostic use and helps identify ignition issues quickly. Premium tools to do the job right - Misfires occur when the sparks jumping the electrode gap are inconsistent with the timing, causing engine stumble or loss of power. This tester provides the necessary visibility to diagnose timing-related problems and confirm root causes. Compact and practical observation tool - This handy small tool lets you observe the spark gap in the tester to determine whether timing is inconsistent, enabling fast and accurate assessments. Use scenarios - Diagnosing a running engine that stumbles, misfires, or loses power: use the tester to verify if ignition components are delivering consistent spark. - Verifying new or replacement spark plugs and ignition leads: test connections and spark delivery before final installation to ensure proper function. - Troubleshooting ignition-related faults during maintenance: isolate faulty contacts, cables, or connections to pinpoint the source of ignition issues.