“The prototype provides two components: a contoured mask and filter housing. No special tools are needed for assembly. The replaceable nonwoven filter materials recommended for the filter housing are widely available. Users will supply and install the elastic or cord.
The mask can be printed in three sizes, all with the same size filter housing. The contoured mask may be more closely molded to the user’s face by submerging the edges in hot water and pressing it to reform the shape against the face.”
The website has detailed instructions for printing and using the masks.
I have printed several of the masks in both polylactic acid (PLA) and acrylonitriel/butadiene/styrene (ABS) plastic. Dolly and I have each tried the masks. Of the three sizes, we prefer the small . When printed in PLA the mask can be softened in hot 140 deg. F water and then molded to the face for a perfect fit.