This is a high-precision filter designed for use in gravimetric analyses. It has a 2.0 micron pore size and a PFA support ring to ensure accurate measurements and minimal moisture fluctuations. The filter is made from Teflon polytetrafluoroethylene and has a 47 mm diameter. It is designed to meet EPA PM5 Reference Method (40 CFR, Part 50, Appendix L) standards. The filter is labelled with a 2-D machine-readable data matrix code serial number and sequential alpha-numeric human-readable serial number on both sides for easy identification and tracking.