Omnipore™ Membrane is hydrophilic PTFE compatible with virually PTFE Membrane Filters, 0.22 0.45 Micron Hydrophobic Mmebrane Membrane Filters. Short Description. Filter Media: Hydrophobic PTFE Diameter: 13mm, 25mm, 47mm, 90mm, 142mm, 293mm. Pore Size: 0.1μm, 0.22μm, 0.45μm, 1.0μm, Millipore® Filter Membranes – Sigma-Aldrich