The Talamex zinc conical shaft anode with feather key for mounting on the shaft end protects the metal parts of the underwater hull from electrochemical corrosion. This sacrificial anode is mounted on the conical end of the drive shaft with the aid of an Allen screw; the moulded feather key prevents twisting. The less noble zinc sacrifices itself for the more noble metals such as the ship's propeller, propeller shaft or sea valves and thus protects 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.