Abstract: A resilient invertible duckbill valve is constructed so that it may be pressed downwardly and folded inwardly upon itself to a stopper position of force-fit within a compression ring to apply a direct lateral compressive force between sealing elements of the valve. This provides additional sealing surface area and very high closing pressure which prevents leakage and a tightly sealed storage condition of a container is achieved when not in use. The valve is conveniently a unitary resilient valve member which is supported by a rigid baseplate that includes an aperture in the center which forms a compression ring around the body of the valve. Both the baseplate and the valve member are releasably held between a threaded cap and top rim of the container.

Abstract: A drinking vessel, preferably a beer mug, includes a sound-generating circuit in the base of the mug which produces a "burping" sound effect. An actuation switch is located in the base which is responsive to the proximity between the bottom of the mug and a support surface upon which it rests. The sound-generating circuit is housed in a bottom portion of the mug which is releasably affixed to the fluid-containing top portion by interlocking lugs and slots. The "burping" sound effect is played only when the vessel is put down on a support surface.