Shaft Zinc Anodes are made of Mil-Spec Zinc Alloy.
All shaft zincs have a copper contact on each half for a
permanent electrical connection. Models X-1 through X-5 have
two stainless steel allen screws. Models X-5A and larger have
four sets of screws. Stainless steel nuts are pressed in, and plastic retaining washers ensure that the screws do not fall out during installation.