The respirator consists of a TPU mask, a PLA filter housing, a 3.75” piece of weather stripping, and elastic bands with adjusters. An optional nose clamp is included that can be glued on if difficulty is encountered getting a seal. The respirator fits 5P71 filters (P95 rating) and 5N11 filters (N95 rating).
The filter housing insert is glued into the face mask with superglue. M4 heat-set inserts or M4 nuts can be used for assembly, be sure to print the correct "Filter Housing Insert" depending on if you want to use heat-set inserts or nuts. The elastic adjusters ("tribars," or "tri-glides") are available for purchase online or can be found on thingiverse.
The intent with this design is to provide a reusable N95 grade respirator for medical professionals during the COVID-19 / Coronavirus crisis. The design has been submitted to NIH for clinical approval.