First up, we have this pair of spark plugs from a industry leading manufacturer NGK, which come already pre-gapped. You may notice straight away that the diameter is ultra-small. It is designed this way to reduce voltage requirement and extend the life of your ignition system. In fact, the iridium electrode is 25% smaller than even a platinum electrode.
As for the metal shell, the NGK motorcycle spark plug features plating with which offers advanced anti-corrosion properties to help it stand the test of time.