PTFE Laminated Membrane Filters, 0.45 Micron, 90mm, 25/Pk PTFE Laminated Membrane Filters, 0.45 micron, 90 mm, pack of 25. Hydrophobic, durable ePTFE laminated on to a polypropylene later. Ideal for venting, phase seperations, and aerosol sampling. SKU PTFE0459025 Manufacturer Sterlitech Pore Size 0.45 Diameter (mm) 90 Pack Size 25 $381.24