Biltema's zinc anodes contain more than 99.5 % pure zinc. For a full result when installing zinc anodes, the new anode should always be roughened up with a stainless steel brush and the attachments checked with an Ohm meter. The must not be any electrical resistance between the anode's attachment and the part to be protected (e.g. engine or propeller).
Biltema's zinc is manufacture in compliance with U.S. MIL. 18001 H, standard for zinc anodes.