NGK SPARK PLUG - Genuine NGK product - Price for 1set / 4pcs NGK IRIDIUM IX Features : - NGK Iridium IX increased performances. - New exterior alloy for a better resistance to extreme temperatures and corrosion related to it. - Top Module made of brass with low impedance (resistance). - Stainless Steel sealing ring (Better resistance & sealing on configurations running at very high pressure). - Better resistance to extreme temperatures and better heat dissipation. - Lifetime from 60 to 80 000 km depending on use. - Linear accelerations thanks to a more stable ignition even at very high rpm. - Ignition performances and durability, regardless of the type of use. - Ignitability optimized, increased HP / Reduction of unburned fuel. - A reliable & easy start at any time. - Improved stability of the idle / Less engine vibrations.