Star Tron Stabilizer+ is perfect for storing vehicles−from motorcycles, boats, lawn equipment, classic cars, and everything in between. Protect your investments while ensuring great start-ups every time. Why stabilize with Enzymes + Corrosion Inhibitors? Enzymes stabilize fuel to keep it fresh and break down contaminants such as gum, varnish, and moisture. Corrosion inhibitors provide an added layer of protection to metal surfaces, helping to fight against internal rust. Directions: Add Star Tron Stabilizer+ to fuel prior to storing to protect against corrosion and fuel breakdown. Remove the cap and pour directly into the tank. WORKS IN ALL GAS ENGINES. Not recommended for diesel fuel.