1. Steel shell: the lower part of the steel shell is fine thread, which is used for matching with the spark plug hole of the cylinder head. The upper part is hexagonal nut, which is used for installing the spark plug sleeve to tighten or screw out the spark plug.
2. The metal rod is the central electrode. The lower end of the metal rod contacts with the upper end of the central electrode through the conductor glass body, and the upper end of the metal rod is equipped with a wiring nut.
3. There is a high alumina ceramic insulator between the steel shell and the central electrode to insulate the central electrode when it is energized.
4. The lowest part of the steel shell is equipped with a curved side electrode.
5. The middle part of the outer steel shell has a copper washer.