This automatic bilge switch incorporates a proprietary electronic sensing technology to detect bilge water levels and trigger pump activation. It has been engineered to operate in any bilge water mixture consistently without failure. Your pump won't be exposed to continuous cycling as the S3 switch can easily distinguish between splashing bilge water, chemicals, sludge buildup, or foam and comes equipped with fully sealed electronics that are completely protected from water or chemical damage. For added convenience, the bilge switch can be mounted on the floor of the bilge, directly to a stringer wall, or alongside the basket of the pump without added components or brackets. The S3 Series switch is also directly compatible with all competitive products and free of moving parts that can jam up, break, or wear out over time. Marine ignition protected and RoHS compliant. Five-year warranty.