Made with three layers of breathable and comfortable fabric. An inner layer of absorbent material such as cotton. A middle disposable filter layer of melt-blown non-woven polypropylene. An outer layer Rayon Acetate Damas.
 
For extra protection and convenience, upgrade your filter to a PP-30-D (PTFE) high-efficiency barrier filter:
 
FDA approved
Filters 99% of particulate matter (0.3 microns), including bacteria and viruses
Hydrophobic, preventing transfer of bodily fluids
Reusable and washable
Low air and moisture resistance allowing for uninhibited breathing