NGK Standard Spark Plugs NGK spark plugs push the limits of performance and innovation, bringing the most advanced technology to today's high-efficiency engines. From the high-tech Ruthenium HX to the industry standard OE-style spark plugs, NGK drives the future of spark plug engineering. Features: Superior construction for serious power NGK makes plugs for almost every application and riding style NGK plugs are versatile with wide operating heat ranges to prevent fouling from running too cool and preignition from running too hot Improved heat dissipation and electrical insulation from high alumina ceramics Deep-seated copper core for a wider heat range and a nickel alloy tip for longer life