Help protect your family from the flu and year-round allergies | This filter drum captures 99% of airborne allergens and viruses, and helps inactivate the H1N1 virus | Compatible with all TruSens Small Air Purifiers | This combination filter has 3 levels of filtration to defend against flu viruses and pollutants in the air | All-in-one filter system combines an anti-viral True HEPA filter with an activated carbon filter and a durable mesh prefilter | 360 degree filtration draws in air from all directions, collecting pollutants from around the room | The filter is at the core of purifying your air and replacement is essential for your purifier to perform at its best | Replace every 12 - 15 months and the Allergy & Flu Carbon Filter every 3 - 4 months (depending on usage) | Change indicator light is displayed on your air purifier when filters need to be replaced | Compatible with all TruSens Small Air Purifiers