Marine PRO is a complete marine fuel system treatment that helps your marine engine run smoother and last longer. Add to fuel to clean fuel injectors and carburetor jets. Cleans and lubricates critical upper engine areas. Helps reduce long-term engine wear. Helps prevent corrosion caused by ethanol and water. Stabilizes tank fuel up to 2 years. Safe for all 2- & 4-stroke gasoline marine engines, inboard and outboard. Marine Pro is a complete marine fuel system treatment. It works in fuel systems to clean and lubricate critical marine engine areas and stabilize fuel up to two years. Safe for all 2- and 4-stroke gasoline marine engines, inboard and outboard.