This set of spark plugs from Autolite is a great addition to your vehicle's ignition system. With a thread diameter of 14mm and hex size of 21mm, they are compatible with a range of models including Range Rover, LeMans, Sunbird and 560SEL. These vintage spark plugs have a copper core and are designed to work with gasoline-fueled engines with a voltage of 12V. The Autolite 66 spark plugs have a standard configuration and can be installed with a depth of .75 inches. They are performance parts that have interchangeable part numbers including 405, 3012, 7082, AG52, BPR4FS-11, and R45XLS. These spark plugs are made in the United States and have an OE/OEM part number of 88901006. Get your vehicle running smoothly with this set of Autolite 66 spark plugs. Exact item lot is shown. New old stock spark plugs with original packaging. Made in USA. No returns on installed items or partial sets. Please review our business policies in our store for information regarding returns, shipping and warranties.