Martyr Anodes are pressure die-cast 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. Martyr anodes provide low cost cathodic protection of ocean-going vessels, structures and equipment constructed of iron, steel, aluminum, magnesium and other metals.Fit & longevityEasy installationNot recommended for use in salt or brackish waterThe only alloy proven to protect your boat in fresh waterWeight: 0.13 kg