This funnel is used to rapidly charge chromatography columns with crude material and solvents without disturbing the stationary phase.
In the same way it can be used for rapid silica gel filtration on a suction fritte. Makes possible substantial simplification and speeding-up of work.
(E.g.: "Dry Column Vacuum Chromatography" by D. S. Pedersen and C.Rosenbohm, Synthesis 2431 (2001)).