Abstract: A respiratory exerciser having a hollow body with three openings. One opening provides access for the user to breathe through the device. The other two openings regulate the inhalation and exhalation resistance, by the use of an aperture in each of two partitions which cover the openings to be brought into and out of alignment with an appropriate orifice in each of two rotatable caps, one cap for each partition. Independent inhalation and exhalation is acheived by the use of a diaphragm which acts as a one way check valve to prevent inhaling air from passing through the hole but allows exhaling air to pass through the hole.