DIY Face Mask Filter Media provides an added layer of protection to homemade and store-bought face masks. Made in the USA, this is the same 100% polypropylene needle punched material that is sold to commercial face mask producers (i.e. medical, dust, paint, etc.). This vital filtering layer, previously only available to the commercial sector, is now available to home mask makers. The material contains an electrical charge to capture particles in the air. Use the filter media as an inside/interfacing layer of a sewn mask or as a removable filter for pocketed masks. Each flat-pack contains a section of filter media, which measures approximately 24 inches x 3 yards, and which can be cut to any size. Typically, each pack has enough filter material to make approximately 108 filters sized 4 inches x 6 inches. Machine washable; lay flat to dry. To iron, use low heat and a pressing cloth for best results. Breathable, high-efficiency Filter Media.