ITEM NAME:Spark plug tester lgnition system coil engine in line auto diagnostic test tooJR Description: 100% brand new Material: aluminium Color: Black Must-have diagnostic tool for any engine with a spark plug When engine won't start, gives instant answer to 'does it have spark?' Simple to use - just remove rubber boot from spark plug, insert tester & place tester boot on plug Turn the engine over - if ignition is being sent to the cylinder, light in tester glows Great time and frustration-saver with cars, motorcycles, boats, chainsaws, lawn mowers & more Size:29.3cm/11.54" Packing: 1 Pc.Simple to use - just remove rubber boot from spark plug, insert tester & place tester boot on plug. Must-have diagnostic tool for any engine with a spark plug. Turn the engine over - if ignition is being sent to the cylinder, light in tester glows.