Designed the Alen T100 and T300 Air Purifiers, the Alen HEPA-OdorCell Filter combines three layers of filter technology to purify the air in your home while destroying heavy odors at a molecular level. Polluted air first passes through Alen’s washable Pre-Filter to capture large particles, extending the life of the filter. In the second layer, air moves through a unique, electrostatically charged HEPA style material that attracts and captures dust, pollen, pet dander, mold spores and other airborne pollutants. In the final layer, clean air passes through hundreds of cells filled with Alen’s patented Molecular Conversion Powder where tough odors like tobacco smoke are destroyed at a molecular level, leaving the air smelling fresh and pure. Note: The HEPA-OdorCell (TF30-MP) Replacement Filter includes two (2) filters. The Alen T300 Air Purifier requires both filters. The Alen T100 Air Purifier requires only one. Instructions for Use: Over time, the HEPA-OdorCell Filter becomes overloaded with particles, decreasing its filtration performance. We recommend regular filter replacements, at least every 6 months with normal use. Rinse or lightly vacuum the removable black Alen Pre-Filter as soon as it develops a layer of visible particles. Allow it to completely dry before replacing. Washing or vacuuming the white HEPA style material will damage the fibers and is not recommended.