Borosilicate glass filtration apparatus accomodates 25mm membrane filters. The new design utilizes a nylon Ace-Thred adapter to join the glass funnel, filter flask and fritted disc together. This design eliminates the need for the clamping device, stopper and base. The unit is easy to assemble, disassemble and clean. The fritted disc can be easily replaced and other porosity discs used. The apparatus is easier to use and more economical than old designs. See 6979-10 flask for use with 3700-04 adapter.