BE SURE TO CHECK OUT NEW VARIETIES REGULARLY!! A fun face mask that comes with a pouch for additional filtration capacity. Two layers of 180 thread cotton in addition to interfacing increases the ability to filter out smaller particles such as viruses, bacteria and dust. Washable. Ties to back of the head. Comes with two 5" fleece squares for added filtration capacity that are also washable. To learn more about materials and how they do against small particles visit Smart Air Filters's Blog that answers your questions. Please also review the CDC's guidelines on cloth masks.