Aviation Spark Plugs With the most automated manufacturing processes and the most innovative spark plug in the aviation industry. Made in USA. High Conductivity Copper Core Center Electrode copper, co-extruded inside a nickel alloy sleeve ensures outstanding heat and electrical conductivity while the nickel sleeve offers high resistance to corrosive combustion gases. High Alumina Ceramic Insulator high mechanical strength, superior dielectric properties, proprietary protective glaze, provides high performance to conquer severe operational conditions. "Clean Collar" massive electrode "V" tip focuses heat to reduce fouling and enhance heat range control. Proprietary Glass Center Seal 21st century 'fired in' resistor replaces the multipart screw, spring, carbon pile stack up used in competitive plugs and known to suffer from resistance value instability that can cause misfires, wasted fuel, engine roughness. Nickel Finish environmentally preferable electrolytic nickel provides outstanding durable finish, superior corrosion protection, and extreme wear resistance. Nickel Ground Electrodes aviation grade nickel electrode design focuses on minimizing sparking voltage requirements while maintaining specification gaps to ensure large, stable 'flame kernels' for on-time ignition and complete combustion. Vacuum Infused Center Electrode proprietary, vacuum infusion process seals electrode/insulator gap providing stable heat range and superior center electrode cooling (heat flow to the insulator). Hot-Lock Assembly intense pressure and heat create positive, zero-leakage, shrunk in seal between insulator and shell to contain the hot, high pressure combustion cycle gases. Harness Wire Contact smooth, uninterrupted, oxide treated spring contact surface offers enhanced corrosion resistance, is chemically bonded to the fired-in resistor providing the ultimate harness/spark plug termination integrity and energy transfer.