Made with a Copper Core Which is a Better Conductor than Platinum and Iridium. Delivers a Stronger Spark Especially in High Performance Application Where High Combustion Pressures Are Present. Copper is Much Better at Dissipating Heat Than Other Materials Which Lessons the Chance of a Misfire. Gapable Allowing You to Open the Gap Exposing a Larger Flame Kernel or Close it if Needed For High Boost Applications. All ACCEL HP Spark Plugs Have Machine Rolled Threads Allowing For a More Precise Thread Engagement and Torque Retention.