PTFE Membrane Filters, 2.0 um, 37mm with PP substrate, Nonsterile, 100 per pack, SF18117. Polytetrafluoroethylene PTFE Membrane Filters with PP substrate, 2.0um, 37mm, Nonsterile, 100 per pack. Regular Price: $104.22. Price $90.63. Live Stock Check - 73 unit (s) Click for more info.