https://www.ciirc.cvut.cz/covid-2/
https://www.rp95.cz/en/
And most rencently, after the 3D printed protoypes turned ot to work very well, an automated assembly line was put togehter in record time:
https://www.ciirc.cvut.cz/seriova-vyroba-ceske-masky-s-nejvy...
The other major technical university - Brno Uiversity of Technology - also developped a 3D printable face mask design:
https://www.vutbr.cz/en/mask
https://www.vutbr.cz/en/but/news-f19528/covid-19-protection-...
In comparion to the mask above, this is a 100% DIY design that one can assemble with common hashold items and a 3D printer.