NGK is setting standards in meeting highest quality demands. By employing progressive engineering we ensure a performance level to satisfy also extreme conditions. Standard Model: * OEM Quality * Triple-Gasket Sealing Process * Consistent Performance * Plug of Choice in Millions of Vehicles Iridium Model: The “secret” of the Iridium IX spark plug is its laser-welded electrode made of iridium. Thanks to its exceptional thin diameter of 0.6 mm it bundles ignition voltage, thus improving combustion at any speed. The engine runs smoothly, the motorcycle accelerates faster. Also, the high-tech metal iridium keeps the distance between the electrodes completely stable, thus preventing the engine from backfiring. Compatible with: - Suzuki: GSX R 750 88-89_M, GSX R 750 90_M, GSX R 750 91_M, XF 650 Freewind_M - Yamaha: R6 01-02_M, R6 03-04_M, R6 05_M, R6 99-00_M