Keep your vehicles radiator and cooling system clean and in perfect working order with Nulon Radiator Flush and Clean. The easy to use, non-acidic cleaner is designed to remove sludge and scale build-up, increasing cooling performance and preparing the cooling system for new coolant in as little as 20 minutes. Nulon Radiator Flush and Clean is ideal for use when changing your coolant, replacing a radiator or trying to clean your cooling system to help increase cooling performance. No premixing is required, it is safe to use with all types of coolants and it won’t harm any cooling system components. 1 bottle will treat most standard passenger cars and small commercials, for larger cooling systems use 1 bottle for every 6L of coolant.