A Miele HEPA filter solves the problem allergy sufferers face each time they vacuum: airborne dust stirred up vacuuming. These particles can actually stay airborne for hours. The filter not only captures and retains tiny particles (including dust, dust mite feces and pollen) it also uses a Generally Activated Charcoal filter (GAC) to absorb odors. Because of its advanced design, a Miele HEPA filter only needs to be replaced after 50 hours of use, or after approximately 12 months.