The DuPont Odor & VOC Filter with True HEPA features a combination filter with 3 levels of filtration to defend against odors. It includes an activated carbon filter, a True HEPA filter and a durable mesh prefilter. The activated carbon filter helps combat cooking and cleaning odors, and reduces airborne VOCs such as ammonia, acetone and formaldehyde. True HEPA filter captures commons pollutants. Dupont 360 filtration draws in air from all directions to collect 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 replace the Odor & VOC Filter Carbon Filter every 3 - 4 months (depending on usage). Change indicator glows red on your air purifier when the filter needs to be replaced. Compatible with the all TruSens Large Air Purifiers.