I got mine today, just an 1cm^2 oval filter with a ~3mm outer
layer of adhesive tape to be glued to each nostril.
Hardly seen by others. Glasses, beard = no problem.
I'll post a picture later.
There is still some breathing resistance and the filters bend in and out
They hold pretty tight when applied correctly, although the shape is not
exactly the shape of my nostril.
They claim that they filter particles greater than 10 micrometers,
so mainly for allergies, dust, smoke. But they claim they also work
for bacteria, even viruses (droplets).
A flu virus is 0.1 micrometer in diameter.
I can imagine that they may increase the surface of these
by bending it like Zieharmonika.
I don't know, whether N95 is possible this way
why those islands ? doesn't make sense to me.
I mean, either the island-material is better or the other material,
don't mix !