The Air/Oxygen Blender is a precision proportioning device for mixing medical grade air and oxygen, which provides oxygen concentration and conveying gas flow controlled oxygen therapy for clinic. Besides as opened-end oxygen delivery, the Air/Oxygen Blender is supporting the use of infant incubator, infant radiant warmer, infant oxygen hood, oxygen therapy instrument, ventilator, CPAP, resuscitator and epidural instrument, etc, especially suitable for neonatal intensive care unit and ward oxygen delivery (Forbidden for the high blood oxygen disease).