These pleated, hand-made, breathable, face masks are not medical grade, but they are made to the specifications of masks I have donated. These all-cotton masks will be a little cooler for summer than my flannel lined masks. They are 2 layers (reversible) of high-quality cotton with elastic ear bands. I added the opening at the bottom of the mask to insert the filter material of your choice (filter not included). The pleated design allows fabric expansion over the nose and mouth for full cove