Diateklity True HEPA Replacement Filter, Compatible Air Purifier Only, Blue 3 Stage Filtration System Pre - Filter can effectively filter hair, fur and other large particles HEPA Filter can effectively filter dust, chemical gas and particles in a diameter of 0.3 micron Special HESA Efficient Activated Carbon Filter can effectively get rid of odors, such as the smell of formaldehyde in the car, TVOC and other harmful chemical gas Recommended replacement cycle: every 3-6 months, depending on use. For Diateklity air cleaner purifier using ONLY!