PTFE for PM2.5 Particle Monitoring, PTFE, hydrophobic, 2.0 µm, 47 mm, white, plain, polypropylene ring, sequential serial number The PTFE Membrane for PM2.5 Particle Monitoring is a filter disc used in conjunction with PM2.5 Environmental Monitoring equipment. - Find MSDS or SDS, a COA, data sheets and more information.