Sierra 18-6158Z Mercruiser Alpha 1 Gen II Anode Kit Zinc Sierra replacement anode kit for use with Mercruiser Alpha One Gen II drives. The anodes found in this kit are constructed of zinc and should be used in saltwater applications only. Sierra high-quality engine parts are designed to meet OEM specifications. For Alpha One Gen II 1991 up Interchangeable with Mercruiser Stern Drive 888756A1 888756Q01 97-888756Q03 California Residents WARNING Cancer and Reproductive Harm - P65Warnings.ca.gov Ot