S-48 Eight-Wire Spark Checker - Highest quality, versatile open-gap spark checker for 1 to 8 cylinders. This "sparky" can be separated into two 4-wire halves by loosening two wing nuts. Furnished with two ground wires for 4-wire use. Sliding mechanism adjusts four gaps which are marked from 1/4 to 1/2 inch as well as in millimeters. Black background for easy visibility is recessed to prevent carbon tracking. Molded Valox is highly resistant to chemical, UV, and physical damage.
 
S-48H Four-Wire Spark Checker - One half of the S-48 Spark Checker. Great for those who don't need more than a four-wire spark checker.
 
S-21 Two-Wire Spark Checker - Handy, economical spark checker for the little kickers. Care must be taken if used on high voltage ignition systems, where arcing can occur from exposed metal on the tester. We recommend the S-48H for CDI (Capacitor Discharge Ignition) systems.