Miele Active AirClean filter fits in S2000, S7000, C1, U1 and S300-S899 series Miele vacuums.
This filter removes 99.95%+ of microns .5 or greater in size and has a thin layer of charcoal to remove unwanted odors from the air. Although not as efficient as the HA-30 HEPA filter it still does a great job at removing odors and dust from blow back into your home.
Miele has recommended changing once a year for standard user volumes (or approx. 50hrs of use). A tab has been added to help users track the life of the filter and maintain optimal performance.