NGK Iridium Spark Plug Set for RE Interceptor 650 / Continental GT650 ( SET OF 2 )NGK Iridium Spark Plug Set for RE Interceptor 650 Continental GT650 ( SET OF 2) These NGK Iridium spark plugs use very precious Iridium metal at the tip of center electrode of diameter 0. 6mm and has a thermo edge design for central electrode. These features give anti carbon fouling performance, smoothest running, and excellent acceleration with increased mileage and are used and appreciated by most racing bikes and cars all over the world. RE