Millex-HV Syringe Filter Unit, 0.45 µm, PVDF, 33 mm, gamma-sterilizable, sterilized: Background Information: Available in 4, 13, 25, 33, and 50 mm diameters with a variety of membranes, Millex® sterile syringe filters are ideal for sterilizing organic solvents, aqueous solutions or air/gas.