ITEM NAME:4 x In-Line Ignition Spark Plug Coil Tester Lead Motorcycle Trailler Tractor Descriptio n Specification: material: plastic Color: black silver Size: 28CM Product List: Auto Spark Plug Ignition Tester*4 Test method: 1 Turn off the engine and disassemble the spark plug coil 2 Connect the black tip of the tester to the spark plug 3 connect the metal end of the tester to the spark plug coil 4 start the engine 5 If the ignition wire is intact, the indicator light flashes Note: 1.Please allow a little size error due to manual measurement. 2.Please be reminded that due to lighting effects and monitor's brightness/contrast settings etc, the color tone of the website's photo and the actual item could be slightly different. Whatever the ending's perfect or not, you can't disappear from my world 4* Spark Plugs.1 Turn off the engine and disassemble the spark plug coil 2 Connect the black tip of the tester to the spark plug. Product List: Auto Spark Plug Ignition Tester 4. 4 Spark Plugs. 5 If the ignition wire is intact, the indicator light flashes.