An apparatus for providing pressure into which a patient must exhale is provided. The canister has a canister axis and is disposed to hold liquid. The canister also has indicia of pressure on the canister. The apparatus also includes a substantially rigid lid disposed to substantially cover a mouth of the canister and having a first inlet through the lid. The apparatus also includes an adapter in the first inlet. The apparatus also includes a conduit being retained by the adapter such that the conduit is substantially immovable relative to the canister axis.