Accel 2418 Spark Plugs (Pair) 6R12 for Harley Davidson Twin Cam Accel High Performance spark plugs for Harley-Davidsons Suitable for all Harley Davidson Twin Cam 1450/1550cc models from 1999 up Spark plugs produce a larger spark for more power at high RPMs. Improves throttle response and fuel economy with less fouling Accel number 2418, replaces OEM part 6R12 Sold in pairs