NGK's Premium RX spark plugs use a new center electrode material containing ruthenium, improving wear resistance and ignition performance, and improving fuel efficiency. - Brand: NGK - Model Name: Premium RX - Features: The new center electrode material contains ruthenium, improving wear resistance and oxidation resistance, and improving ignition performance. - Performance: Improves fuel efficiency. Thank you for viewing. Premium RX Plug LFR6ARX-11P [95515] Set of 8, One Car's Worth, Premium RX PLUG, Made by NGK Thank you for viewing. I intended to use these for an Insight ZE2, but they are no longer needed, so I am selling them. Please research the compatible vehicles yourself. If you want to buy them individually, it will be 4 for 6000 yen. Please comment if you would like to do so. Please refrain from price negotiations.