It's for compact non-pressurized solar water heater!
Cleaning: Magnesium alloy sacrificial anode formed one power plant and electromagnetic vibration by current in the container or piping. Physical structure of the salt in water (mainly Calcium carbonate) change to Sparse flow-like. If there is already thick scale in container or piping, then the scale will be impacted and cut off by electromagnetic vibration.
(2)protect water heater, water containers of steel structure,
(3)protect the gas pipeline in-home service polarization high resistance electrolytes (soil and water in the steel structure)