13MM Non-Sterile PES Syringe Filter, 0.22 uM or 0.45 uM Pore Sizes, 13 Diameter Disc, 100/Pack. 13MM Non-Sterile PES syringe filters, $70/pack of 100, 0.22 and 0.45 micron. Made with polyethersulfone (PES). Free ground shipping on orders $200 and up. Membrane Solutions PES is an inherently hydrophilic membrane whose wettability has been proved