Volvo Penta Transom Shield Zinc Anode | Canada Metals CM873395Z Martyr zinc anode designed to protect the transom shield from corrosion in salt water. Volvo Penta transom block anode Zinc anode for salt water applications For TSK SX-MHP transom applications Replaces Volvo Penta 873395 For magnesium see p/n CM873395M For aluminum see p/n CM873395A