The Talamex spherical aluminium shaft anode protects the metal parts of the underwater hull of boats from electrochemical corrosion, especially in fresh water and brackish water. The anode is mounted on the propeller shaft and the less noble aluminium sacrifices itself for the more noble metals such as the propeller, drive shaft or sea valves, thus protecting them from pitting. As a rule, the anode must be replaced annually during winter storage, or twice a year in the case of very severe degradation.