Honda Internal Anode Metal - 12155-ZY3-010. Important: Quantity varies by location. See requirements below.. BF200A - Cylinder Block: 2 required. BF200A - Mount Case: 2 required. BF225D - Cylinder Block: 2 required. BF225D - Mount Case: 2 required. BF250D - Cylinder Block: 2 required. BF250D - Mount Case: 2 required. Help protect your Honda outboard from internal corrosion with the genuine Honda internal anode metal, part number 12155-ZY3-010. These sacrificial anodes are installed in key internal locations such as the cylinder block and mount case, where they are designed to corrode first and reduce galvanic corrosion on more expensive engine components. Replacing worn anodes on schedule supports cooling efficiency and long-term reliability in harsh marine conditions.. Key Features. Genuine Honda internal anode metal for corrosion protection. Used in internal locations such as cylinder block and mount case (by application). Sacrificial design helps protect internal engine components f