This filter drum is engineered with an increased amount of activated carbon to help eliminate odors and airborne VOCs. In addition, a True HEPA filter captures common pollutants in the air. Compatible with all Small TruSens Air Purifiers. This combination filter has 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 common pollutants. 360 degree 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 Small Air Purifiers.