I recently purchased and installed these, but have only used them for about 20 kilometers. My vehicle's idling speed increased slightly, so I've switched back to the normal spark plugs. I'm selling these at a low price, so please take this opportunity if you're interested. I also purchased a new spark plug wrench for the installation, but it's not the normal spark plug size, so I'll include it. These are used items, so please refrain from purchasing if you are sensitive to this. Also, returns are not accepted to prevent swapping. These 360° MultiSpark Plugs achieve highly efficient ignition, supporting improved fuel efficiency and reduced emissions. - Model: 360° MultiSpark Plug - Quantity: Set of 4 - Accessories: Spark plug wrench - Brand: MINI DELTA - Features: Low emissions, high fuel efficiency Shipping will be via Takkyubin Compact.