The Pack of 4 Spark Plug-Copper Plus Champion Spark Plug 434 RC9MC4 consists of high-quality spark plugs made by Champion Spark Plug. These spark plugs are crafted from durable copper material, ensuring reliable performance for your vehicle's ignition system. The manufacturer part number 434 indicates the specific model of the spark plug, and the California Prop 65 Warning signifies the presence of nickel in the product. This pack of spark plugs is a dependable choice for maintaining optimal engine functionality in your car or truck.