You look scary. But in a medical Metter like this, the choice of protection cannot be based on scary looking.
Better to be live and look scary than be handsome in coffin. Some life-hack for you. Instead of using costly 3M filters attached to 3M respirator you can place small pieces of medical cotton into compartments with membranes for inhaled breath and cover them with the shreds of papers used for ULPA filters. In turn that coverings cab be fixed tightly by rubber bands of appropriate diameter. I'm using bands cut off from the end of children balloons.
Good comment, but why should I believe you are correct?
If you can show a simple method to test the efficiency of your materials when used as described, that would be quite valuable. I'm good with making filters for the masks, but if I run out and make them, I'll have devised a testing method to insure that my product does perform adequately. Otherwise a person would be relying on sheer guess work and essentially killing himself.
Well, such testing methods require sophisticated equipment and reagents. I hardly think you have that at home. However you can switch on your logic and compare the size (~ 0.12 µm,) of Covid with that one for pores (~0.1 µm) in ULPA paper which is widely used in bacteria oriented filters. Besides, airborne viruses have a tendency to form conglomerates that increases the dangerous particle size by 2x-3x times. You can advance and use 2-3 layers of that paper. The 0.5 - 1 cm thick piece of medical cotton adds extra protection layer. Sure DYOR.