ABN Automotive Spark Plug, Wire, Coil Tester &ndash; Universal Inline Diagnosis Light Bulb Tool Car, Motorcycle, Small Engine Practical: The ABN Automotive Spark Plug, Wire, Coil Tester  Universal Inline Diagnosis Light Bulb Tool Car, Motorcycle, Small Engine is a quick diagnostic tool to know if the plug is firing Versatile: Tests spark plugs, spark plug wires, and coils on cars, motorcycles, lawn mowers, and other small engines Safe: Wont puncture or damage the wire; Check the spark without having to pull a wire Easy to Use: Run the engine and a flashing light bulb indicates a live and functioning wire or plug; Clearly see if your spark plug wires are delivering a spark to your plugs Easy Storage: Compact design (about the size of a pen) with a pocket clip allows for simple transportation and easy storage