These Reversible Masks are made from 100% quilting cotton. The doubled, internal filter is made of polypropylene, which is a non-woven, waterproof material. The area above the nose has an internal wire, that can be pinched for a tighter fit. Hand wash and dry only. Do Not Microwave, as the elastic can start a fire, as well as the Nosepiece. CoVid Regulations prevent a return of the mask.