The filter is at the core of purifying your air. Filter replacement is essential for your purifier to perform at its best. 360 degree filtration draws in air from all directions, collecting pollutants from around the room that may affect allergy & symptoms. Washable prefilter offers the first level of defense against dust & pet hair. Handwash with mild soap as needed. Carbon filter captures odors & certain gasses. HEPA Type filter removes pollutants as small as 0.3 microns that's roughly 30 times smaller than a strand of hair. Replace every 12 to 15 months (depending on usage). Change indicator light is displayed on your air purifier when filters need to be replaced. Compatible with TruSens Air Purifiers. Air Purifier Filter Type: HEPA / Activated Carbon; Filtration For: Dust; Pollutants; Air Cleaner Compatibility: TruSens Air Purifiers; Width: 8.5".