12 inch x 6 inch Divers Dream Aluminum Hull Anode | Martyr CMDIVERA Premium aluminum Martyr anode protects boat's hull from corrosion in salt or brackish water. Divers Dream sacrificial anode Aluminum anode is for use in brackish and salt water applications Martyr anodes are made of a high purity specialized alloy based on the US Mil Spec Bolt-on style anode is designed to mount to hull 12 in. length 6 in. height 1/2 in. thickness