Sterile PES Syringe Filter, Single Packed, 0.22 uM or 0.45 uM Pore Sizes, 13 Diameter Disc, 100/Pack. 13MM Sterile PES syringe filter, $70/pack of 100, 0.22 and 0.45 micron, single packed. Made with polyethersulfone (PES). Free ground shipping on orders $200 and up.