Bosch 79026/WR8AC Copper with Nickel Spark Plugs feature a heavy-duty Nickel center electrode for a longer lasting service life compared to standard Copper plugs. Additional features include a Copper core that provides better heat transfer for resistance to pre-ignition and fouling, metal glass fused resistor that maximizes interference suppression, ribbed insulator design that prevents misfire due to current leakage, and Nickel-plated rolled threads that provide superior resistance to corrosion. Nickel plated threads eliminate the need for anti-seize, ensuring easy installation and removal.