3-ply single use filters designed to fit into our Reusable Face Masks designs. Intended for single use, slide one inside your reusable face mask filter pocket before each use. Made from the same materials as our single use face mask. Outer layer: PP non-woven. Middle/Filter layer: melt-blown PP non-woven. Inside layer: PP- non-woven. Filter filtration effectiveness specifications: BFE greater or equal to 95%. Filters are individually sealed and packaged in a bag in increments of 10.