Performance Tool W86554 Inline Ignition Spark Tester

Inline Ignition Spark Tester, Easily connects between the spark plug and spark plug wire. With the engine running, the tool flashes a mirror image of ignition spark. Quick and easy test helps check the condition of the ignition system at each cylinder. Troubleshoot dirty spark plug connections, defective points, bad cables or connections, and more. Shows voltage to plug, a stronger voltage will create a brighter light.