The Hercules Cryo-Tek original antifreeze is designed for use in hydronic heating and cooling closed-loop systems, most solar heating systems, snow melts, radiant heating, and general plumbing systems. The antifreeze is a ready-to-use, 45% virgin propylene glycol formula, containing a triple-protection inhibitor that stabilizes pH to prevent corrosion and chelated, hard-water minerals, while also inhibiting scale and sediment formation. Hercules antifreeze can be used in systems fabricated with metal, plastics and rubber piping, fittings, seals, and other parts. WWW.OATEY.COM