Mercury - Mercruiser 92-8M0172753 Mercury Corrosion Guard 12oz Aerosol Genuine OEM Mercury-Mercruiser part. Mercury Corrosion Guard Engine Protect is a corrosion inhibitor that protects metal parts. It is designed for harsher, humid environments and creates a protective film that seals our air, salt, and moisture. Corrosion guard is lightweight, non-staining, and will not harm paints, plastics, or rubber. Marine engine corrosion inhibitor Lightweight formula remains clear Engineered for saltwate