The product is a set of 4 Denso Iridium Long Life spark plugs designed for a 2013-2014 Mercedes-Benz GLK350. These spark plugs are a direct replacement with standard configuration and are manufactured in Japan. They are made with nickel material and have a polished nickel finish. The spark plugs offer a 1-year manufacturer warranty and are designed for gasoline fuel type. This performance part is guaranteed to enhance the ignition system of the vehicle.