The Arieltek Mercury Mariner Switch Box CDI is a vital component designed for Mercury Mariner engines manufactured between 1972 to 1977, specifically tailored for 20 horsepower models. Replacing OEM part numbers 332-4911A2, 18-5786, and 114-4911, this switch box ensures optimal ignition performance, offering reliability and precision in controlling the engine's ignition system. Crafted to meet or exceed OEM specifications, it ensures compatibility and seamless integration, providing peace of mind for efficient engine operation and performance.