It provides the ultimate in cold weather and corrosion protection. It prevents marine engine cooling systems and boat, RV and home plumbing systems from bursting in cold weather. Its premium additive package prevents corrosion of aluminum, copper, brass and solder, and will not harm rubber seals, or hose materials. The 3X died blue-green color provides excellent blow through visibility. Formulated with non toxic, virgin propylene glycol (30% blend). Glycerin free formula. Provides burst protection to -100°F (-73°C).Provides freeze protection within a range of -58°F to -63°F (-50°C to -52°C).This product is ready to use or may be diluted. Follow label instructions for dilution ratios.