0.22 0.45 Micron Hydrophobic PTFE Membrane Filters Disc - Hawach As a PTFE membrane filter manufacturer, Hawach provide a series of pore sizes (0.1μm, 0.22μm, 0.45μm, 1.0μm, 3.0μm, 5.0μm, 10μm), high porosity, large dirt holding capacity, recoil and high temperature disinfection; good pressure resistance.