The product is a 4-piece Autolite Iridium XP XP104 Spark Plug set designed for direct replacement in vehicles. It includes interchange part numbers from top brands such as DENSO, NGK, Champion, Bosch, and General Motors. The spark plugs are genuine Autolite Iridium XP and come with a core charge of free. This spark plug kit is an essential component for the ignition system, providing reliable and efficient performance for your vehicle..