Miele Active Airclean Filter SF-AA 50 is designed to keep your environment fresh by effectively neutralizing and absorbing odors with its active charcoal layer. This filter not only improves air quality but also features a convenient TimeStrip that gradually releases a red liquid line over the course of one year, providing a clear reminder when it’s time to replace the filter. This ensures your air filtration system remains efficient and your space stays clean and odor-.