GREENCOOL 400 is an extra-concentrated coolant for a heavy-duty engine cooler. In other words, this coolant needs dilution. GREENCOOL 400 consists of corrosion inhibitors from the Organic Acid Technology (OAT) group, providing anti-crust and fouling prevention for closed-cycle cooling systems. This product works excellently to prevent overheating, rust and scale in various application conditions. Before use, GREENCOOL 400 requires water dilution.