The size of the holes in the mask stops nothing but very large particles.
I suppose it's important to define
“very large particles”.
Based on my microscopic examination of a genuine 3M-brand N95 mask, I wouldn't count on it to stop anything smaller than about fifty microns, though I think they are supposed to be 95% effective against particles as small as about three microns.
The #CoronaHoax2020 ranges in size from about 0.05 to 0.2 of a micron. That is really, really, really tiny. Most light-based microscopes are not capable of resolving detail that small. You need something more exotic, such as an electron microscope to see something that small.
By contrast, the gaps in an N95 mask are clearly visible in my microscope, at a relatively low-power configuration. The image that I've been posting was taken using my 15× eyepiece, which is the highest power eyepiece I have (I also have 5× and 10× eyepieces), and my 10× objective (I also have 5×, 50×, 60× and 100× objectives).
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To give some frame of reference for those that aren't familiar with such small units of measurement:
A micron is a millionth of a meter.
Most people might be familiar with a millimeter; that is 1⁄1000 of a meter. The smallest ticks on most metric rulers are millimeters. Very roughly, about 1⁄25 of an inch. A micron is 1⁄1000 of that. About the smallest thing that you can see with the unaided human eye, if your vision is good, and viewing conditions are optimal, is about 100 microns, or 1⁄10 of a millimeter.