They come in a lot of different flavors. I have been fit-tested several times with success. Some are definitely easier than others. Do I think that every 0.3

They come in a lot of different flavors. I have been fit-tested several times with success. Some are definitely easier than others. Do I think that every 0.3 micron or above particle is getting filtered out by the mask for the duration that I wear one? Not really, but I do believe confidently that it is getting the vast majority. Certainly enough to measurably reduce risk.