Rust needs free-electrons to form. The strong positive charge on the Anodes (Rust Magnets™) attract the negative free-electrons away from the structure and they now corrode rather than the steel.
Any steel contains millions of free-electrons which are negatively charged and move around in the metal due to positive and negative charge differences caused mainly by impurities in the steel.
The Anodes (Rust Magnets™)
now corrode rather than the steel structure.