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. SPARK PLUGS 75-99BT (COLD