Honda Internal Anode Metal - 12155-ZV5-010. Important: Two required per engine.. Help protect your Honda outboard from internal corrosion with the genuine Honda internal anode metal, part number 12155-ZV5-010. These sacrificial anodes are located inside the water passages on both the intake and exhaust side, where they are designed to corrode first and reduce damage to critical engine components in harsh marine conditions.. Key Features. Genuine Honda internal anode metal for corrosion protection. Two required per engine. Located inside water passages on both intake and exhaust sides. Sacrificial design helps protect internal engine components from corrosion. Ideal for preventative maintenance and routine corrosion control. Fitment. Honda BF25A through BF250D. Why It Matters. Cooling passages are constantly exposed to water and minerals that can accelerate corrosion over time. Internal anodes are engineered to take the hit first, helping protect expensive internal surfaces and maintain