A valve, comprising: a main body portion comprising a peripheral wall defining an interior space and an internal wall separating the internal space into first and second internal passages, a first aperture extending radially through the peripheral wall, connecting the first internal passage to an environment external to the main body, and a second aperture extending radially through the peripheral wall, connecting the second internal passage to the environment; a trach body portion disposed adjacent to the main body portion, the trach body portion defining a third internal passage; a flapper valve sandwiched between the main body portion and the trach body portion; a first adjustment ring having a third aperture therethrough, the first adjustment ring being disposed on the main body portion so that the third aperture is in register with the first aperture, the first adjustment ring being movable with respect to the main body portion to permit alteration of the positional relationship between the first and third apertures to alter a size of a first opening defined by the first and third apertures; and a second adjustment ring having a fourth aperture therethrough, the second adjustment ring being disposed on the main body portion so that the fourth aperture is in register with the second aperture, the second adjustment ring being movable with respect to the main body portion to permit alteration of the positional relationship between the second and fourth apertures to alter a size of a second opening defined by the second and fourth apertures. a main body portion comprising a peripheral wall defining an interior space and an internal wall separating the internal space into first and second internal passages, a first aperture extending radially through the peripheral wall, connecting the first internal passage to an environment external to the main body, and a second aperture extending radially through the peripheral wall, connecting the second internal passage to the environment; a peripheral wall defining an interior space and an internal wall separating the internal space into first and second internal passages, a first aperture extending radially through the peripheral wall, connecting the first internal passage to an environment external to the main body, and a second aperture extending radially through the peripheral wall, connecting the second internal passage to the environment; a trach body portion disposed adjacent to the main body portion, the trach body portion defining a third internal passage; a flapper valve sandwiched between the main body portion and the trach body portion; a first adjustment ring having a third aperture therethrough, the first adjustment ring being disposed on the main body portion so that the third aperture is in register with the first aperture, the first adjustment ring being movable with respect to the main body portion to permit alteration of the positional relationship between the first and third apertures to alter a size of a first opening defined by the first and third apertures; and a second adjustment ring having a fourth aperture therethrough, the second adjustment ring being disposed on the main body portion so that the fourth aperture is in register with the second aperture, the second adjustment ring being movable with respect to the main body portion to permit alteration of the positional relationship between the second and fourth apertures to alter a size of a second opening defined by the second and fourth apertures.