The EYQUEM C 42 S is a spark plug specifically designed for the classic Citroën 11CV and 15CV models. This high-quality spark plug guarantees optimal ignition and durability, essential for the older engines of classic cars. With its specially designed electrode configuration, it offers a consistent spark even in extreme conditions. It is crucial for vintage car owners to maintain authentic performance and reliability. Using this spark plug ensures efficient fuel combustion and helps reduce malfunctions, resulting in a smoother-running engine and extending the car's lifespan.