Concentrated formula which contains 100% propylene glycol with special inhibitors and protectants. Winterizes both salt and freshwater systems as well as potable water systems, engine blocks and heads. Safe for copper, brass and all plastic except acetate. Provides freeze protection to -100 deg F when used undiluted. Lubricates and helps prevent seal dryout and plastic deterioration. Add water according to chart on bottle for desired protection level. Sold in case lots of 6.