This 2 pack of Rudder/Trim TAB ZINC anodes are a must-have for any marine enthusiast. The anodes are made of high-quality zinc and have a diameter of 3-3/4 inches. They are compatible with a variety of outboard engines and are designed to provide excellent performance and durability. The Camp brand and R-3 manufacturer part number ensure that you are getting a top-quality product that will meet your needs. These anodes are perfect for use on boats and other marine vessels.