... without pump, toghther with 4.0G plastic tank (RO,ro purifier without pump,reverse osmosis) Features:Stage 1: ... smell in water and filter organic chemical pollution.Stage 4: RO membrane which remove bacteria, Virus, Corpuscule, other solute ... air, then prevent from second-hand pollution. (RO,ro purifier without pump,reverse osmosis) RO style without pump sediment filters(RO,ro purifier without pump)