Self-inflating gas bags inflate automatically, eliminating the need for a compressed gas source. When these devices are used to deliver oxygen, the bag needs to be compressed with each breath. A “tail” attached to the reservoir can increase the oxygen content of the delivered gas by reducing the amount of entrained room air. Even with a gas source of 1 FiO2, when no reservoir is utilized, the oxygen received by the patient is greatly reduced to about 40 percent. To deliver free-flow oxygen when utilizing a self-inflating bag, it is necessary to remove the oxygen tubing and deliver the oxygen flow directly to the infant’s nares. It is important to have all self-inflating or flow-modulating bags attached to a pressure manometer so that the applied pressure can be closely monitored.