Corrosion Guard Engine Protect 8M0172754 is an easy to use, spray rust inhibitor that forms a water resistant barrier on non‑painted and painted surfaces. It is designed for use in harsher, humid environments marine engines are frequently exposed to. Use Quicksilver Corrosion Guard Engine Protect to prevent rust from forming on outboard powerheads and other under-cowl areas, inboard & sterndrive engines and other metal surfaces. Can also be used to help displace moisture to start wet engines and it penetrates existing rust to help loosen seized parts. Do not spray into air inlet or throttle body and avoid spraying on drive belt systems. Can also be used elsewhere on the boat, on motor vehicles, ATV/UTV, motorcycles, bicycles, tools, or other metals you want to provide with long-lasting corrosion protection.