A type of coffee maker consisting of a flask and a funnel/filter.
It works by having one put a small heat source under the flask filled with water. Hot water vapor pressure then pushes water up into the funnel. Coffee is added to the funnel and mixed in. Then, with the heat source taken away, a vacuum in the flask pulls the coffee back through the filter and into the lower flask again. The filter can then be detached, and the flask and base of the siphon used to serve the coffee.