MetaPurex nano-porous aluminum oxide (AAO) ceramic discs converts your standard Buchner filter into a nano-filtration device. Fits selected  Buchner funnel filters, 90 mm diameter.  Pore size of 60 nm with a maximum variation of 10%. Membrane thickness is 50 microns.  Micro-crack free heat sealed edges requires no o-ring protection, providing an effective larger filtration surface.