Martyr - Ground Plate Anode Grounding plates consist of thousands of bronze balls casted into a porous plate. The porosity makes this a great option for electrical bonding systems. These can able be used for grounding on RF systems such as SSB and Loran antennas. CM10421422 - 456 x 151 x 12mm Surface area coverage - 8.9 m^2 (95 sq ft) Product Information: Washer material: Bronze/gold-plated Bolt material: Bronze/gold-plated Nut material: Bronze/gold-plated Why Martyr? Martyr Anodes provide low cost marine cathodic protection for boats, marine structures, and boat equipment. Often called "Boat Zincs”, Martyr Anodes are made of a specialized alloy based on the US Military Spec using only high purity metals. Martyr is the only manufacturer that offers all three alloys that protect your boat from corrosion that can occur in salt water, brackish water, and freshwater. Our anodes are pressure die-cast and manufactured to strict quality standards through an ISO 9001 Quality Management system and are guaranteed to be manufactured to US Military Alloy Specifications. We manufacture sacrificial zinc anodes, aluminum anodes, and magnesium anodes, all of which are proven to prevent boat corrosion that leads to pitting to the hull plate, rudders, and bilge keels. Martyr anodes also protect propellers, shafts, shaft brackets, stern tubes, engines, and rudders.