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 with a hepa type filter for trapping small particles. The trusens combination filter has been engineered to collect microscopic particles, allergens and volatile organic components (voc#s), and odourous gases 360 degree filtration draws in air from all directions. Collects pollutants such basic household odours and airborne allergens. Carbon prefilter captures odours and certain gasses, offering the first level of defense. Hepa type filter removes pollutants as small as 0.3 Microns. Change indicator light is displayed on purifier when filters need to be replaced. Compatible with trusens z1000 air purifier