An apparatus for use in treating a respiratory disorder comprising: a housing; a pneumatic block comprising an air path therein, the pneumatic block comprising a pneumatic block inlet, an inlet tube, a pneumatic block outlet, a blower configured to supply a flow of air, a flow plate, and a blower sleeve, the blower including a blower inlet and a blower outlet; a device outlet fluidly coupled to the blower and configured to be coupled to an air circuit to deliver the flow of air to a patient interface for treating a respiratory disorder; and a chassis configured to locate the housing, the pneumatic block and the device outlet, the chassis comprising a dock for removably receiving a humidifier reservoir, the humidifier reservoir being configured for receiving a flow of air from the pneumatic block and delivering the flow of air to the device outlet when inserted in the dock, wherein the flow plate divides the interior of the pneumatic block into a first chamber (4020c1), a second chamber (4020c2) and the interior of the blower sleeve, wherein the pneumatic block is configured such that the flow of air: enters the pneumatic block through the pneumatic block inlet and enters the inlet tube, is delivered through the inlet tube to the the first chamber (4020c1), is delivered from the first chamber (4020c1) to the second chamber (4020c2) through a plurality of flow tubes located on the flow plate, is delivered from the second chamber (4020c2) to the blower through the blower inlet, is pressurised in the blower, exits the blower through the blower outlet, exits the pneumatic block through the pneumatic block outlet. a housing; a pneumatic block comprising an air path therein, the pneumatic block comprising a pneumatic block inlet, an inlet tube, a pneumatic block outlet, a blower configured to supply a flow of air, a flow plate, and a blower sleeve, the blower including a blower inlet and a blower outlet; a device outlet fluidly coupled to the blower and configured to be coupled to an air circuit to deliver the flow of air to a patient interface for treating a respiratory disorder; and a chassis configured to locate the housing, the pneumatic block and the device outlet, the chassis comprising a dock for removably receiving a humidifier reservoir, the humidifier reservoir being configured for receiving a flow of air from the pneumatic block and delivering the flow of air to the device outlet when inserted in the dock, wherein the flow plate divides the interior of the pneumatic block into a first chamber (4020c1), a second chamber (4020c2) and the interior of the blower sleeve, wherein the pneumatic block is configured such that the flow of air: enters the pneumatic block through the pneumatic block inlet and enters the inlet tube, is delivered through the inlet tube to the the first chamber (4020c1), is delivered from the first chamber (4020c1) to the second chamber (4020c2) through a plurality of flow tubes located on the flow plate, is delivered from the second chamber (4020c2) to the blower through the blower inlet, is pressurised in the blower, exits the blower through the blower outlet, exits the pneumatic block through the pneumatic block outlet. enters the pneumatic block through the pneumatic block inlet and enters the inlet tube, is delivered through the inlet tube to the the first chamber (4020c1), is delivered from the first chamber (4020c1) to the second chamber (4020c2) through a plurality of flow tubes located on the flow plate, is delivered from the second chamber (4020c2) to the blower through the blower inlet, is pressurised in the blower, exits the blower through the blower outlet, exits the pneumatic block through the pneumatic block outlet.