as exhalation gas pressure is applied from below these flaps will open along the cut lines to let gas escape from the mouthpiece fig4 is an outside view of the device showing again the elevational relationship between the circular connector 12 its back wall 13 connecting to the higher level mouth shaped end piece 14 the valve housing is made a part of the mouth shaped end piece 16 above where it connects to the circular connector fig5 is a top view of the device without the retaining ring 28 and valve disc 26 the support structure for the valve disc 26 is made up of the ring surface 18 the three grille arms 22 and the central hub 20 the end of the mouth shaped piece that is placed in the patient 39 s mouth has a greater width than the opposite end where the valve housing is located the mouth end has an oval opening to better anatomically fit in the patient 39 s mouth fig6 a d illustrate various cut patterns for the valve disc 26 in 6 a each of six radial cuts the center form a flap 41 on either side of the cut in conjunction with annular cuts so as to provide twelve flaps which can open up in response to the exhalation pressure in 6 b there.