RMI-25 restores the additive package to your antifreeze. RMI-25 is a liquid consisting of a pH Stabilizer for acid/alkaline balance, an Oxygen Scavenger to prevent cavitation, erosion and cylinder pitting. A Lubricant for seals, hoses and water pumps. A Cleaner that breaks down rust, scale and corrosive deposits. These deposits are changed from solids to a soft floating harmless gel-like material. These dissolved solids will not recombine or form blockages in the cooling system. After a period of time the dissolved solids will purge out of the system and into the coolant recovery tank. In the case of vehicles with coolant filters the dissolved materials will trap in the filter. In a couple weeks of driving, a dirty system will be nearly clean. This cleaning action is continuous when engine is in operation. Once clean metal status is reached an organic barrier is then formed on the clean metal preventing further contamination. Water Conditioning is accomplished by a surfactant agent, improving heat transfer, making water more efficient than coolant itself. You get 2 treatments in the 8oz bottle because you only need 1/2 of the 8oz bottle for a Datsun 510.