Prime Guard Premium -50 propylene glycol base high-grade antifreeze for complete freeze protection requirements. Protects recreational vehicles and summer cottages, and swimming pools from water system freeze up to -50 deg. burst. Nontoxic and tasteless. Safe for fresh water systems. Inhibit fouling and corrosion while preventing algae growth. Helps lubricate pumps and valves throughout the system. 100% concentrate - no mixing required.