This ready-to-use, biodegradable, non-toxic propylene glycol formula contains no nitrates, borates, amines, silicates or phosphates that can clog thermostats or cooling systems. Provides year-round protection against boilover (256°) and freezing (-26°) and meets or exceeds all OEM specifications so it won't void warranties. Safe for all aluminum, copper, iron and other metal surfaces as well as welds, gaskets and seals. Seals pinhole leaks and fissures and passivates metal surfaces to prevent corrosion. Protects up to 4,000 hours. Sold in case packs only.