A long stem funnel made of polypropylene (PP) is a laboratory apparatus used for transferring liquids into containers with small openings. A funnel with a very long stem on it is called a thistle tube. It is a specialized piece of laboratory equipment that is used to add liquids to flasks or other glassware during an experiment. For example, the long tube can be connected to a stopper so that liquids can be added to a flask through the stopper.