Use to test spark plug circuits, electronic fuel injection signals and idle air control circuits. Includes:23970 In-Line Spark Checker Kit for Recessed PlugsThis is a must for testing newer vehicles with recessed spark plugs.Can also be used to test conventional and coil-on plug ignition systems8 Noid Lights for checking GM PFI, FORD TBI, GEO TBI, BOSCH PFI, GM TBI, GM SCPI, BOSCH 2 and GM MULTEC 22 IAC Test Lights for straight and 90? applications.Features:Quickly diagnose "no start? and engine misses conditions in the electrical fuel injection and spark plug circuits.Analyze rough running engines.Supplied with instructions in a durable, plastic molded storage case.Patent No. 7,129,705.S and G Tool Aid 36350 In-Line Spark Checker for Recessed Plugs, Noid Lights & IAC Test Lights Kit