Drag Specialties Spark Plugs - '75-'99 Big Twin - E18-6657SDS

Plugs have a unique look with a black ceramic body and bold red logo/script. Insulator is made of 95% pure alumina, features strong resistance to heat shock and superior insulation. Multi-rib design of the insulator eliminates flashover. Nickel-plated housing prevents oxidation and corrosion. Multi-layer gaskets and heat crimping process ensure a leak-free, gas-tight seal. Copper core electrode prevents oxidation and corrosion, has good electrical and heat conductivity and creates long spark plug service life.