E3.39 is often in used in Honda, Suzuki, Yamaha, and other high RPM engines. The patented DiamondFIRE ground electrode is secured to the shell with two legs to help facilitate heat transfer, and to withstand the intense vibration of powersport engine applications. The unique DiamondFIRE side wire is proven to increase power, reduce fuel consumption and improve hydrocarbon emissions in long-term use. The E3 ground electrode and full-size center electrode also provides optimal performance over an extended product life.
NGK - CPR6EA9, CPR7EA9, CPR7EIX9
HD - HD6R10