Does this item come with a stopper?

Yes, this item comes with a silicone #8 stopper.

Could this (Item No.: D0047P - 47mm Polysulfone Filter Holder w/ Funnel & Base) fit into Item No.: H389410000 - 1000mL Vacuum Flask.

Yes, the stopper that comes with the filter holder does fit snugly into the neck of that vacuum flask.

How do you take it apart?

To remove the funnel top from the base you simply twist it off.

how does the funnel attach to the support? Is it magnetic or twisted on?

This funnel is a twist on.

Do you have a question?

Email me the answer?