Non-Intrusive ignition coil tester, easy to use and saves time. Instantly verify an active or inactive ignition coil by simply placing the sensing tip near the coil while engine is cranking or running at idle. During normal operation, an ignition coil creates an open magnetic field each and every time the coil is energized. By placing the sensing tip of the tool near or against the ignition coil, a blue LED will illuminate each time a magnetic field is detected.