Compatibility: Compatible with Therapure TPP220F and Therapure TPP220M filters. Air Quality Improvement: Filtration is rated H13 and removes up to 99.97% of airborne particles as small as 0.3 microns in size including dust, smoke, pollen, pet hair and dander, mold spores and dust mites. Airtight Seal: Foam gasket seal for high performance filtration directs air through the filter and keeps air from escaping around the sides. Maintenance: Recommended to change this filter once every six (6) months and more often under harsh air conditions. Pack Size: Each package contains two (2) replacement filters. Filter-Monster branded replacement for Therapure TPP220M filter removes smoke, dust, pollen, pet dander, mold spores and dust mites from the air