I saw this type of face masks on a 'building tools' store (like home depot), and on the label said, among other things in chinese and english, non medical.
In this KN95 Masks Explained mentions
These masks, like NIOSH N95 masks, provide protection from 95% of particles that are greater than .3 microns in diameter.
However do they also protect even when says non medical?
I've got one and as you can see the only difference with a medical mask is the FDA label (notice the upper RHS, there is none), as pointed out by @BobE. The brand is exactly the same.
inside the cover was this paper
Here is the pic with the FDA label (notice the upper RHS, the FDA label)