Technical specification Double layer natural fabric masks (cotton, linen, bamboo) with internal pocket for filter insertion. A more antibacterial wash at 40 degrees is recommended, to prevent the design from being damaged. Iron inside out REUSABLE AND WASHABLE Internal fabric: Organic Cotton, hypoallergenic, untreated. Great for prolonged contact with the skin, even for the little ones. Mask produced pursuant to art. 16, paragraph 2, of the D.L. 18/2020 They are not a medical surgical device nor a DPI and do not fall within the application of the UNI EN 149 standard However, they can be used with aids such as filters that you can easily buy at the pharmacy. My intent is to make "filter covers" nice enough not to feel uncomfortable (more than that).