NGK BUHX Surface Gap plugs have trivalent metal plating the provides superior anti-corrosion and anti-seizing properties. These motorcycle spark plugs are nearly immune to pre-ignition and usually require a special high-energy ignition system. They may be necessary for high-compression applications, but can be susceptible to fouling—especially in colder applications. BUHX Surface Gap plugs feature a semi-surface discharge. Order the plugs recommended for your bike application.