Vidcast:   https://youtu.be/a3IPszUQiI0   There are a gazillion fancy decorator masks, and many provide filters to slide into cloth pockets.  The dirty secret: most won’t give you optimal protection.  I’ll teach you how to make them the safest possible.   The filters that come with the masks have a PM 2.5 specification. They can filter up to 90% of particles as small as 2.5 microns.  Covid is 0.1 microns and may get through.   You can use the provided filter as a pattern to cut a piece of HEPA filter paper from a HEPA H13 vacuum cleaner bag that is constructed of medical grade polypropylene and not fiberglass.   Make certain that the mask fits tightly to your face.   https://medifyair.com/blogs/blog-feed/medical-grade-hepa-true-hepa-and-hepa-type-what-s-the-difference   https://niiceface.com/pages/pm2-5-filters   Soniclean Upright HEPA Filter Bags https://www.amazon.com/dp/B07Q5KWGKM/ref=cm_sw_r_cp_tai_6LZJFb9XGK4HB   #masks #filter #hepa #pm2.5