The NGK BUHW-2 surface gap plugs have no side electrode to pre-gap and are nearly immune to pre-ignition (knocking). Surface gap plugs have no heat range listing as the electrode design prevents the firing tip from overheating causing pre-ignition. Use only the spark plug listed in your engine owner’s manual. Using the wrong plug can reducing optimum performance, reduce fuel economy or cause damage to your engine. Spark plugs are easy to change with common spark plug sockets. The NGK pure alumina silicate ceramic insulator provides superior strength, reduces breakage and better heat transfer. The Ribbed Suppressor Seal extends resistance and prevents spark “flash over” and misfire plus the triple seal helps prevent leakage. The Quicksilver brand is the leader in delivering uncompromising engine oils, parts and accessories to the marine industry for over 65 years. Quicksilver is the premier supplier of Mercury Marine Original Equipment replacement engine parts, oils, and accessories, but also works to serve all Original Equipment brands in the marine and powersports industries. It has earned a loyal following by providing the highest quality products that are tested through some of the most rigorous environments and testing procedures. No aftermarket company comes close to the level of research and design as Quicksilver; buying Quicksilver is buying performance, protection and peace of mind.