These masks are made with double protection and have a soft, breathable cotton lining and a polyester outer layer of fabric. An inside pocket in the cotton lining allows for the use of filters for additional protection. Each mask comes with two sets of filters. Elastic bands that fit around ears can be adjusted to fit most sizes. Please note these are not medical grade. One size fits most. Machine wash and line dry for easy care. These are non-returnable due to the sensitive nature of this product & come individually wrapped.