Corrosion Protection: They actively protect the steel inner lining of a water tank from rust.
Sacrificial Mechanism: Magnesium is highly reactive, so it corrodes and degrades via electrolysis instead of the tank itself.
Brass Threaded Plug: The golden threaded end screws directly into the tank wall or elements to provide a water-tight seal.
Lifespan Extension: Regularly replacing these rods prevents tank leaks and significantly extends the life of the heating system.