This set of 4 water separator sensors is designed to be a direct replacement for the Mercury part number 8M0021043. These sensors play a crucial role in monitoring and separating water from fuel, ensuring optimal performance and longevity of the engine. Each sensor features high-quality construction and reliable functionality, suitable for various marine applications. With easy installation in mind, these sensors come equipped with connectors that fit seamlessly into existing electrical systems. Ideal for both professional marine mechanics and DIY boat owners, this replacement set guarantees better engine efficiency and reduced risk of fuel contamination.