I was hoping these masks would be free breathing and could be something I could comfortably wear when pushing myself on the bike. They are not. There is very little air passing through the fabric. If you wear glasses they will be steamed. These are fine to wear at work or to the store, but because this was offered through this store, it would be good for cycling. I did not find that to be true.
Simple, straightforward masks. They fit well (I have the MD/LG) without being too big. The double layer of fabric seems about right - thick enough and sufficiently close weave to be effective as a mask, but not so thick that it impedes breathing hard while exercising. They are not specifically rated for smoke, but seem to help a bit with the current poor air quality in the Western US.
Sooo...I have used dust masks, paper masks, surgical masks, homemade whatchamacallit masks. You get the idea. So far these have been the most comfortable masks because the straps that go over and under your ear are adjustable independent of one another and the higher nose keeps it in place.
These masks look nice on your face and ear loops can be adjusted to fit. However, it is almost impossible to breath through them. I bought 4 of these, and keep them in the car in case I forgot a mask. If you wear glasses, it definitely fog up the glasses.