joint 110 such as by a snap fit or a threaded screw connection the opep device 112 also includes a mouthpiece 112 which may either be formed as an integral part of the housing 102 or removably attached to the housing 102 although the mouthpiece 112 is shown as being cylindrical in shape the mouthpiece 112 could be any number of alternative sizes or shapes to accommodate various users of the opep device 100 such as children or adults a chamber inlet 114 positioned within the mouthpiece 112 is configured to receive exhaled air into the chamber 108 in view of the description below it should be apparent that the cross sectional area of the chamber inlet 114 is an important variable affecting the exhalation pressure generated at the mouth of a user and maybe modified or selectively replaced according to the desired operating conditions a side perspective view of the opep device 100 is shown in fig2 the opep device 100 further comprises at least one chamber outlet 116 configured to permit exhaled air to exit the chamber 108 the at least one chamber outlet 116 may comprise any number of apertures having any shape or size furthermore the at least one chamber outlet 116 maybe located elsewhere on the housing 102 the opep device 100 may also include a grate 117 to prevent unwanted objects from entering housing 102 referring to fig3 a cross sectional side view of the opep device 100 shows the internal components of the.