This is a set of 4 NGK Premium RX spark plugs that were used in a ZC33S. The heat range is 7. I purchased these new from a shop, installed them, and used them for approximately 12,000 km. Part number: LKR7ARX-P STOCK NO. 90020 These were removed due to changes in the vehicle's specifications. Please also see the close-up of the electrode. There were no particular problems. I believe they are still usable, but please bid only if you understand that they are used items. They will be shipped in the original box.