This system is often used with air-entrainment nebulizers to provide humidification and oxygen therapy. The total flow of gas (oxygen plus the entrained air) will be greater than the patient's peak inspiratory flow so the delivered FIO2 is independent of their respiratory pattern.
This system is frequently utilized to provide humidification and oxygen therapy using air-entrainment nebulizers.  The total gas flow (oxygen plus entrained air) exceeds the patient's peak inhalation rate, ensuring a consistent FIO2 regardless of their breathing patterns.