Boater's Dream Hull Anode – AluminumPerformance Metals exclusive replacement for Diver's Anode. The anode has twice the surface area and protection and  2 1\/2 times the life of a standard diver's anode.Performance Metals Navalloy® aluminum anodes are manufactured to the military specification MIL-DTL 24779 and are suitable for use in all water types- salt, brackish, or fresh.The anode includes the exclusive, patented “red spot” wear indicator.