Usage Information: The H2O 4 CPAP Mini EZ Distilled Water Filtration System is designed specifically use for CPAP and BiPAP machines and heated humidifiers. It should not be used to purify drinking water; but it can be used for other products where distilled water is suggested such as steam irons, car batteries, plants and fish tanks. Unlike conventional drinking water filter pitchers which do not remove calcium, our H2O 4 CPAP Mini ion-distilled filtering cartridge is designed specifically to remove calcium and other minerals from tap water to protect the health of sleep apnea patients. Simply insert one of the new filter cartridges into the H2O 4 CPAP Mini base unit and pour tap water into top of the bottle. In just minutes the unit makes ion-distilled water ready for use in a variety of applications.