ENOC EN-COOL EXTRA is a superior quality engine coolant formulated from high purity nonethylene glycol and organic acid carboxylate technology corrosion inhibitors with proven heat transfer performance. It provides excellent corrosion protection for all metals in cooling systems of gasoline and diesel engines, especially the principle metals, iron, copper and aluminum. It is available diluted with de-ionized water at 33% and 50% concentrations of ENCOOL EXTRA coolant. EN-COOL EXTRA is free from potentially harmful additives such as nitrites, amines and phosphates and as such contributes to a safer environment.