Aluminum anode kit 8M0116589 is for use on Mercury Verado 350hp L6 outboards (serial No. 1B7 16557 and above). The kit includes all anodes and attaching hardware for the transom bracket and gear case of the engine. These aluminum anodes are for freshwater or saltwater use. The anodes are important in the prevention of corrosion of aluminum or stainless steel engine parts. Inspect anodes periodically for best protection and replace when seeing signs of corrosion or pitting. Never paint an anode. See your owner's manual or service manual for specific applications and replacement instructions.