Wynns Cooling System Flush is a concentrated product designed to thoroughly clean all automotive cooling systems. It features a dual-action formula that removes scale and eliminates rust, deposits, and oily residues. This cleaner is acid-free and performs excellently with all types of cooling liquids, including OAT coolant. It keeps dirt and particulates in suspension while cleaning and is safe for rubber hoses, seals, and all metals within the cooling system. This flush is recommended when changing cooling liquid and is particularly effective for cleaning older cooling systems. One bottle treats up to 7 liters of coolant.