The Champion RJ-12Y Spark Plugs are a set of 8 vintage parts designed for gasoline engines. With a thread diameter of 14mm and made of copper material, these spark plugs are suitable for ignition systems requiring 12V voltage. The Manufacturer Part Number RJ-12Y ensures compatibility and quality assurance in automotive applications. Ideal for car and truck owners looking for reliable spark plug replacements, these Champion spark plugs offer a dependable performance for smooth and efficient engine operation.