This set of 8 Champion RBL13Y copper spark plugs is a great choice for anyone looking to replace their old and worn out spark plugs. These spark plugs are designed with a 14mm thread diameter and a standard configuration, making them easy to install and use. Made from high-quality copper material, these spark plugs are durable and long-lasting, ensuring that your vehicle's ignition system will run smoothly and efficiently. In addition, these spark plugs have a voltage of 12V and an installation depth of 10.9mm (0.42\"), providing optimal performance and reliability. They are also compatible with various interchange and OE/OEM part numbers, including 665 and R43TS. Manufactured in the United States, these spark plugs are a vintage part that will help keep your vehicle running smoothly for years to come. Lot of 8 New vintage Champion plugs shown. Made in the USA. Please review our business policies in our store for information regarding returns, shipping and warranties.