Quicksilver 8M0172754 Corrosion Guard Engine Protect - 12 oz Genuine OEM Mercury-Mercruiser part. Lightweight corrosion inhibitor formula designed to protect engines from rust and oxidation in freshwater and saltwater environments. Special Order Item Features Marine engine corrosion inhibitor Lightweight formula remains clear Engineered for saltwater and freshwater environments 12 fl. oz. spray can Corrosion Guard Engine Protect formula is engineered for marine engine blocks and metal components