Hot selling Auto Car Test tester Ignition Spark Indicator Plugs Wires Coils Diagnostic Tool fit for all carADD730 Ingition Spark IndicatorDescription:With the engine running,place the grooved end of the tool over the spark plug wire. The bulb will flash to indicate spark tool tests spark plugs.spark pug wires.ad coils without puncturing the wire.Package Including:1pc x Ignition Spark Indicator