Aluminum anodes ��� For use in saltwater or freshwater. This is a complete anode kit to replace all factory installed anodes found on the transom and gearcase. Fasteners are included. Fits Mercury/Mariner: 135���200HP 4 cylinder Verado, 75���115 (1.5L) and 135���250HP (2.5L and 3.0L) Optimax engines.