PTFE Laminated Membrane Filters, 0.45 Micron, 47mm, 100/Pk. PTFE Laminated Membrane Filters, 0.45 micron, 47 mm, pack of 100. Hydrophobic, durable ePTFE laminated on to a polypropylene later. Ideal for venting, phase seperations, and aerosol sampling. SKU.