The Wynn's 45941 Cooling System Cleaner is a high-performance solution designed to thoroughly clean the cooling systems of petrol and diesel engines. It effectively removes rust, scale, and oily deposits, restoring optimal heat transfer and ensuring efficient operation of control elements. This cleaner performs excellently in all types of cooling liquids, including OAT coolants, and is safe for rubber hoses, seals, and all metals within the cooling system. It keeps dirt in suspension to prevent re-deposition and is extremely effective in all closed-circuit liquid cooling systems. One 325 ml bottle treats cooling systems ranging from 5 to 12 liters.