NGK 7986 Spark Plug Install ready! Non-directional swirl finish eliminating the need to machine. Also aids in proper seating of friction faster "break-in". Manufactured to meet or exceed Original Equipment (OE) fit, form, and function at ISO/TS16949 certified facilities. Tight-tolerance specifications reduce thickness variations and lateral run-out to ensure a balanced rotor. Manufactured to match SAE J431 metallurgical engineering standards for consistent quality, strength and performance. On rotors, exact OEM vane design and configuration are followed.