NGK sparkplugs are manufactured to precise tolerances as well, and designed to perform consistently in a crucial component. The key function of spark plugs is… well, to make a spark so that the air-fuel mixture can ignite, in turn firing the engine's pistons and creating power. NGK technologies of note: copra core (good heat removal); spot welded (no crimping) nickel-plated electrode--better wear and corrosion resistant; triple-gasket sealing reduces gas leakage. Along with engine performance, these properties also extend the longevity of the spark plug. Because of their vast span of endorsement, NGK spark plugs are favored by numerous original equipment manufacturers (OEMs) and customers in the car, cruiser, marine and little motor applications; it is the reason the NGK brand has solid market value.