Mil Spec Alloy Includes all necessary anodes, hardware and install instructions Aluminum Alloy for use in salt & brackish (mixed) water Anodes are inexpensive which means it is important to protect your boat with a quality product. Martyr anodes are pressure diecast and manufactured to strict quality standards through an ISO 9001 Quality Management System. In addition, each alloy is guaranteed to be manufactured to the latest US Military Alloy Specification and is chemically tested regularly in our in-house labs to ensure consistency. Copies of Material Certificate of Compliance are available upon request. Poorly manufactured anodes may contain high levels of impurities such as iron, which will leave you investment unprotected. Martyr Anodes provide low cost cathodic protection of ocean going vessels, structures and equipment constructed of iron, steel, aluminum, magnesium, and other metals.