Embittered to help deter ingestion. Ready to use. Do not add water. Protects to -34 degrees F. New formulation recommended for conventional gasoline and diesel engine cooling systems. Universal low silicate formulation. Autoguard Ready to Use is a conventional green colored, universal low silicate antifreeze formulated for use in automotive and heavy-duty applications. When used in heavy-duty applications, the addition of separate Supplemental Coolant Additives (SCAs) is required. Recommended for all conventional aluminum and metal cooling systems. Made in USA.