Spark Plugs – ’99-’22 Twin Cam/XL

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