Honda Cylinder Head Anode Metal - 12155-ZZ5-000. Important: 2 required per engine.. Help protect your Honda outboard from internal corrosion with the genuine Honda cylinder head anode metal, part number 12155-ZZ5-000. This sacrificial anode is designed to corrode first, helping reduce galvanic corrosion inside the engine and protecting more expensive cylinder head and cooling passage surfaces in harsh marine conditions.. Key Features. Genuine Honda cylinder head anode metal for corrosion protection. Important: 2 required per engine. Sacrificial design helps protect cylinder head and internal water passages. Ideal for routine maintenance and preventative corrosion control. OEM fit and function for compatible Honda applications. Fitment. Honda BF40DK2. Honda BF40DK4. Honda BF50DK2. Honda BF50DK4. Why It Matters. Cylinder head anodes are designed to wear out over time as they protect internal metal surfaces from corrosion. Inspect anodes regularly and replace them when they show significa