E3 Spark Plugs are the product of years of fundamental research in the combustion field. The unique patented electrode configuration of these new E3 spark plugs increases the amount of combustion pressure created during each power stroke of an engine， which results in a marked increase in power output， fuel economy， and reduced emissions in all gasoline engines. Product Features:E3's DiamondFire edge to edge electrode provides maximum performance with increased efficiency and a faster more complete burn. Quicker Starts - The patented edge to edge design concentrates spark energy resulting in easy starts in all conditions. Energy - Increases both two and four cycle engine power up to 12% over conventional spark plugs. Efficiency - Fuel consumption reduced up to 13% in small engines. Emissions - E3's advanced spark technology produces cleaner burning combustion; toxic emission in long term use reduced up to 58%. E3 Spark Plugs are pre-gapped at the factory to meet O.E. requirements. E3 Lawn & Garden spark plugs are warranted against wear， defects in materials and workmanship for a limited lifetime. This warranty does not cover plugs installed in any modified engine or used in any racing， aircraft， or commercial application. Spark plugs damaged by abuse， accidents， or improper installation or applications are not covered by this warranty.