Left to right: a neck gaiter (aka a buff) that slips over the head; a KN95 respirator, a version of the N95 respirator used in U.S. hospitals; a pleated surgical mask (below the KN95); a cloth mask.

Left to right: a neck gaiter (aka a buff) that slips over the head; a KN95 respirator, a version of the N95 respirator used in U.S. hospitals; a pleated surgical mask (below the KN95); a cloth mask.