I'm selling aftermarket parts in preparation for changing cars. These are NGK iridium spark plugs, so you can be assured of their quality. Heat range: 7, ISO type Used on a ZC31S Swift Sport Mileage: Approximately 1250km There's plenty of life left, so I think they can be used without any problems. I used them without any issues until I removed them. Please make sure they are compatible with your vehicle. Please understand that these are used parts before purchasing. Keywords: Trust GReddy NGK Plug Spark Plug Swift Swift Sport ZC 31 Racing Plug Iridium