These protective facial masks are double layered (twp-ply) and made from 100% polypropylene. The elastic band wraps around your ears and keep the mask securely in place, creating a one size fits most adults protective face mask. These masks are durable, washable, and reusable for added convenience. Material(s): Polypropylene; Size Group: One Size Fits All.. These protective facial masks are double layered (twp-ply) and made from 100% polypropylene. The elastic band wraps around your ears and keep the mask securely in place, creating a one size fits most adults protective face mask. These masks are durable, washable, and reusable for added convenience.