Anti-corrosion & Seizing Protection: Trivalent Metal Plating Sealed for Leakage Prevention: Triple Gasket Heat Dissipation & Conductivity: Solid 98% Pure Copper Core Enhanced Insulation: High Grade Alumina Silicate Ceramic Reliable OE Performance: Nickel Alloy Design Reliable NGK Standard spark plugs, packaged in the signature 'yellow box', have been trusted for generations. Tailored for OE use, they deliver OE-quality nickel alloy performance and design. NGK's renowned high-grade alumina silicate ceramic enhances insulation for optimal dielectric performance, while triple gasket sealing halts combustion gas leakage. A solid 98% pure copper core ensures superior heat dissipation, conductivity, and wide heat ranges. Trivalent metal plating provides superior anti-corrosion and anti-seizing properties.