Aluminum anodes are recommended for salt or brackish water & are also a suitable substitute for magnesium anodes in fresh water. Replaces Merc Part Number: 97-806189, 806189A1, 97-806189Q1 Replaces Sierra Part Number: 18-6067A Complete Anode Kit and Hardware for Mercury Mercruiser Alpha 1 Gen 2 Sterndrive Includes Mounting Bolts Aluminum Anode good for Saltwater & Bracking... Aluminum Trim Cylinder Anode Kit for 1991 & Up Mercruiser Alpha One Generation 2 Sterndrives. Replaces Merc Part Number: 97-806189, 806189A1, 97-806189Q1 00042A Mercruiser Alpha 1 Gen II Trim Cylinder Anode Replaces 806189 Anodes For Boats Aluminum Alloy Cavitation Plate Anode 821629Q1 Fit For Mercruiser Alpha One Generation Ii Sterndrive 1991 Onwards Alpha One Gen 2 Impeller Kit Replaces Sierra Part Number: 18-6067A The Brush Research BC1224 BC 1/2 ( 12 .77MM) Brake Cylinder Flex-Hone 240SC Grit is a versatile tool for surface finishing and cross hole deburring in brake cylinders , wheel cylinders , hydraulics, pneumatics, and valve guides They are very helpful if you use your boat in fresh & salt water as magnesium anodes are not recommended for salt or brackish water.