This set of 4 Champion spark plugs with stock number 406 and model RV12YC is an excellent choice for your ignition system. Made of high-quality copper and designed with a resistor, these spark plugs ensure reliable performance and longevity. They are compatible with a variety of vehicles and are easy to install. Whether you need to replace your worn-out spark plugs or upgrade your ignition system, this Champion set is a great option. Get your engine running smoothly with these reliable spark plugs.The main box was opened. None of the spark plug boxes were opened. They are all new never used. Enjoy💥