Champion N12YC / OE015/T10 COPPER PLUS Spark Plug. Copper-core center electrode, patented Ultrasealâ„¢ coated shell for maximum corrosion resistance, patented SAC-9 semiconductor resistor. Connector type: M4/SAE. Electrode Gap [mm]: 0.9. Quality/ Grade: Nickel gro. Spanner Size: 21 mm. Spark Plug: 1 - Earthed Electrode; with gasket seat. Spark Position [mm]: 3.0. Technical Information Number: N12YC. Thread Length [mm]: 19. Thread Size: M14x1,25.