Quick view Lisle 20610 Inline Spark Tester Quickly diagnose problems with all ignition systems. With the engine running, the tool flashes a mirror image of ignition spark. Connect the tool between the spark plug and the plug wire. The tool is double-ended to offer a straight boot and a 90boot on... MSRP: $18.10 Now: $8.00 Add to Cart Compare Quick view Lisle Lisle 20610 Inline Spark Tester MSRP: $18.10 Now: $8.00 Add to Cart Compare Compare Selected × OK Give to Houston Habitat! Every Donation Furthers Our Mission Donate!