3-STAGE AIR PURIFICATION: Stage 1: Pre-filter; Stage 2: Activated carbon filter; Stage 3: True HEPA filter CAPTURE + ELIMINATE HARMFUL PARTICLES: Our filter cleans your air from 99.97% of particles as small as 0.3 microns like dust, pollen, pet dander, smoke, and household odors BREATHE EASIER: True HEPA filters improve air quality by reducing allergens and improving sleep quality LONG-LASTING: For optimal performance, change your PureZone 3-in-1 True HEPA filter every 6 months COMPATIBILITY: 3-in-1 air filter designed for the PureZone Air Purifier (sold separately) Breathe in fresher air using the 3-in-1 True HEPA replacement filter from Pure Enrichment. Enjoy improved air quality as the premium 3-stage filter safely cleans the air in any home or office. Our filter is designed to work with Pure Enrichment's PureZone Air Purifier (sold separately). Each of the three layers of this filter provides a unique level of cleaning: Pre-Filter: Captures initial dust and allergen particles. Activated Carbon Filter: Absorbs formaldehyde, benzene, and other noxious gases. HEPA Filter: Captures dust, smoke, pollen, and other allergens. For optimal performance, we recommend replacing your unit's air filter every 6 months.