Overview Reviews Product Description Connect the tool between the spark plug and the plug wire. The short wire is double ended to offer a straight boot and a 90-degree boot on one tool. With the engine running, the tool flashes a mirror image of the ignition spark. The additional 7" extension plug wire is used on coil-on-plugs that are recessed and hard-to-reach. Lisle Tools Catalog Product Videos Custom Field Harmonization code HTS #9031809080 Manufacturing country US Product Reviews Write a Review Write a Review × Lisle Inline Spark Tester w/ Coil On Plug Wire 20580 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Review Subject * Comments *