Surface gap plugs are nearly immune to pre-ignition, and usually require a special high energy ignition system. They can be susceptible to fouling, especially in colder applications, but may be necessary in high compression applications.Trivalent metal plating provides superior anti-corrosion and anti-seizing propertiesCorrugated ribs prevent flashoverPure alumina silicate ceramic insulator, provides superior strength and better heat transferCopper core aids in heat removalTriple seals prevent leakage