This lot of 3 Champion 861ECO Eco-Clean spark plugs is designed for use in 4-cycle engines. These spark plugs have a 13/16in configuration and are perfect for those looking for performance/custom fitment. The OE/OEM part number for this product is 861ECO and the manufacturer part number is also 861ECO. These spark plugs are ideal for those working on ignition systems and components for cars and trucks. With the Champion brand, you can trust that you are getting a high-quality product. Upgrade your vehicle with these spark plugs and experience improved performance.