Not a perfect fit. This is one of my least favorite parts of the high capacity column. The stopper is just slightly too small and can be pushed completely into the top of the column and I'm afraid it leaks a bit of steam. It is also just too tall which causes it to obstruct the outlet opening just slightly. It has also started to disintegrate a bit around the edges after only a few dozen runs. The column is otherwise amazing and this is the weakest part of the design.