3-ply face mask — meaning it has three layers: an outer layer, a middle filter layer, and an inner comfort layer.
The mask is black in color, and many such masks are marketed as non-medical / general-use face coverings (i.e. for everyday use: dust, allergens, general public settings, etc.).
The “antimicrobial finish” refers to a special treatment applied — often to the fabric — that helps inhibit the growth of odor-causing bacteria (and possibly other microbes) in the mask material.