Tecnoseal R5MG Rudder Anode - Magnesium - 5" Diameter Anodes For Boats Tecnoseal R3MG Rudder Anode Magnesium 334 Diameter R3MG – D&B Marine Supplies Magnesium Anodes For Boats Alpha 2 Pack Tecnoseal Anode Kit W/Hardware - Mercury Alpha 1 Gen 2 - Zinc Trim Plate Anode - Aluminum Flat Mercury Alpha for EnginesPlate for TrimMaterial: AluminumPounds: 0.19 lbsKg: 0,080 kgHeight: 0.91" Tecnoseal R3mg Rudder Anode Magnesium 3-3/4 Diameter Easy installation underwater Bolt retaining washers prevent the anode from falling off