True HEPA filtration removes up to 99.97% of airborne particles as small as 0.3 microns in size including smoke, dust, pollen, pet dander, mold spores and dust mites Engineered to be compatible with Therapure TPP220 filter , TPP220FL-FM1 Recommended to replace every six (6) months, or more often in harsh environments, for maximum efficiency Package contains one (1) filter Approximate Dimensions: 12.5 x 4.38 x 2.12 Filter-Monster branded replacement compatible withTherapure TPP220M filter removes smoke, dust, pollen, pet dander, mold spores, and dust mites from the air.