The product is a set of 4 NGK 6987 Spark Plugs designed for gasoline vehicles. These spark plugs have a thread diameter of 14mm and are made of nickel material. They are standard configuration spark plugs with a voltage of 6V and weigh 0.8 lbs. The manufacturer part number is 6987, and they are interchangeable with other part numbers such as ZFR6F11G, ZFR6F-11G, and NGK 6987 ZFR6F11G. The spark plugs are made in the United States and come with a California Prop 65 Warning for nickel.