Feb 15, 2022 · Dec 21, 2021 · 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. 13 25 33mm wheel Syringe Filter with 0.22 0.45 micron . Wheel Syringe Filter with 0.22 0.45 micron hydrophobic PTFE Membrane.