Leitz TruSens Replacement 2-in-1 Particulate Filter Drum for TruSens Z-1000 Air Purifier. The filter is at the core of purifying your air and replacing it is essential for optimal air purifier performance. This 2-in-1 filter combines a carbon prefilter for capturing large particles like hair and dust with a filter for trapping ultra-fine airborne particles. The Leitz TruSens combination filter has been engineered to collect ultra-fine airborne particles, allergens, volatile organic compounds (VOC's), and odorous gases The Leitz TruSens combination filter has been engineered to collect ultra-fine airborne particles, allergens, volatile organic compounds (VOC's), and odorous gases. 360 degree filtration draws in air from all directions, collecting pollutants from around the room that may cause allergies and other symptoms. Carbon prefilter captures certain odours and gases, and offers the first level of defence against dust and pet hair. Filter removes pollutants as small as 0.033 microns. Change indicator light is displayed on purifier when filters need to be replaced.