• Flexible lead type spark plug tester • Test for non-start conditions and for spark strength • Simulates spark plug under compression load • Standard ignition minimum spark plug gap indicated by 'S' • Electronic ignition minimum gap (10mm) indicated by 'E' • When gauging voltage turn tester screw counter-clockwise to increase gap • 2kV marking: (2/0) • 3kV marking: (3/0) • 4 kV marking: (4/0) Type: Spark Tester