A pouring device for transferring liquids can be attached to the neck of a vessel and has two basic parts made of plastic. One basic part is designed as a threaded sleeve with an internal thread and an external thread and can be screwed onto the neck of the vessel, that thread being used which is also used when attaching a customary screw-on stopper serving as a closure. The other basic part forms the actual pouring device and is designed as a bellows which consists of an elastic, stretchable and flexible material. Said bellows can be deformed and thus positioned, but it maintains its deformation position. It can thus be moved back into its starting position by a simple movement by hand.
