FLT4825 filter replacements are compatible with Guardian AC4825, AC4825E, AC4300BPTCA, AC4850PT, and AC4900CA air purifiers. Note: Not compatible with the AC5000 Series air purifiers. 2.6 Extra Pre-Filters: Extend the life of the HEPA by changing the pre-filter more frequently. Activated carbon pre-filter reduces odors and VOCs from cooking, smoking, pets and more. High-Efficiency Filtration: The H13 true HEPA filter captures 99.97% of airborne particles as small as 0.3 microns. Value Pack: The package includes 3 true HEPA filters and 9 pre-filters for up to 18 months of use. Save money and hassle by buying in bulk and enjoy fresh air every moment. Use scenarios: - In busy kitchens to control cooking odors and smoke alongside daily air purification. - In homes with pets or allergy sufferers to reduce pet dander, odors, and VOC exposure. - In bedrooms or small offices where consistent clean air supports better sleep and concentration.