This 2-in-1 filter combines a carbon prefilter for capturing large particles like hair and dust with a HEPA type filter for trapping small particles. The TruSens combination filter has been engineered to collect microscopic particles, allergens and volatile organic components (VOC’s), and odorous gases. 360 degree filtration draws in air from all directions, collecting pollutants such basic household odors and airborne allergens. Carbon prefilter captures odors and certain gasses, and offers the first level of defense against dust and pet hair. HEPA Type filter removes pollutants as small as 0.3 microns – that’s roughly 30 times smaller than a strand of hair. Change indicator light is displayed on purifier when filters need to be replaced. Not Washable. Life expentancy of 12 - 15 months. 7.3 x 7.3 x 3.7 in. Sold by each.