The Frigoboat FBE51525 zinc anode is an essential component for cathodic protection of marine refrigeration systems utilizing keel coolers. Manufactured with a zinc alloy that meets or exceeds U.S. Military Specification (US Mil-A-18001), this anode is designed for saltwater environments and is not recommended for use in freshwater. Its installation helps prevent galvanic corrosion on submerged metal components, thereby extending the lifespan of the refrigeration system.