MGDUFF ZD57LKIT hanging zinc sacrificial hull / mooring anode, suitable for use in salt waters. Sacrificial anodes should be fitted and correctly bonded to all boats / vessels to help prevent corrosion by cathodic protection when in the water. The MGDUFF zinc hanging anode kit features an interchangeable anode system allowing the anode material to be replaced without disturbing the bonding system unlike traditional hanging anodes which have the wire cast into the anode material and once consumed the whole system has to be disposed of - which can help save time and money.