This Viking Valknut face mask is lightweight, breathable, and stylishly designed with everyday work in mind. Made of 100% cotton with silk thread embroidery, it is multi-layered and has a sleeve so you can slide an additional disposable filter into the pocket if desired. The one size fits all construction, combined with adjustable elastic straps behind each ear, provides a snug fit. It even fits well over beards! Machine washable. Note: These masks are not graded for medical use.