Check the listing for details. Car Spark Plug Tester Diagnostic Tools Engine Start Test In-Line Igniton (D). Condition: New, Made in China. Listed at 8.80 USD. Features: Quickly diagnose ignition system problems, lack or no spark condition. Easily test ignition circuit continuity at each cylinder. Find dirty spark plugs, defective points, bad cables or connections, etc. The tool connects between the spark plug and the plug wire. Great for trouble shooting all internal combustion engines. Specifications: Length: 270 mm (10.8inch) Material: Stainless Steel and Plastic Suitable for: Testing the car ignition system work To Use: With Engine Off, Remove Spark Plug Wire Attach Black Connector to Spark Plug Insert Metal End of Tester Into Spark Plug Wire Try to Start the Engine If Ignition Circuit is Complete, Bulb will Flash Package Included: 1 x Spark Plug Tester.