The Leitz TruSens Replacement 2-In-1 Particulate Air Filter has been engineered to collect ultra-fine airborne particles including bacteria, viruses, dust, allergens, pet dander, volatile organic components (VOCs) and odorous gases. The filter has 360 degree filtration that draws in air from all directions, collecting pollutants from around the room that may affect allergies and other symptoms. The carbon prefilter captures odours and certain gases, and offers the first level of defence against dust and pet hair. The Change indicator light is displayed on the air purifier when filters need to be replaced. It is compatible with Leitz TruSens Z-1000 Small Air Purifier.