Büchner funnel 70mm used in filtration. It is traditionally made of porcelain, but glass & plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a fritted glass disc/perforated plate separating it from the funnel. Filter paper is placed on the plate, and the filter paper is moistened with a liquid to prevent initial leakage. The liquid to be filtered is poured into the cylinder and drawn through the perforated plate/fritted glass disc by vacuum suction.