Machine rolled threads prevent seizing or cross threading during installation and removal. Copper-glass seal bonds center electrode and insulator for a gas-tight seal.

Denso iridium long life spark plugs are factory installed on luxury vehicles by automakers such as GM, Toyota, Honda and Mitsubishi.

0. Copper-glass seal bonds center electrode and insulator for a gas-tight seal. Purified alumina powder insulator provides exceptional strength and thermal conductivity.