“Regarding these airway devices I am understanding they are like a snorkel in a sense they have a malleable flange that rests between the teeth and lips. Ventilating with this device is accomplished by pressing against the lower and upper lips. It does use an oral pharyngeal type of airway that presses against the teeth and the two parts line up. It could very well be advantages in a controlled clinical setting like the operating room but not that practical in the field.
This you tube video might better explain the message that is conveyed: