National Geographic : 2013 Aug
Why two tiers are better than one. Smaller cyclones generate high G-forces. Arranging them across two tiers increases airflow. The new DC47 has 2 Tier RadialTM cyclones that capture more microscopic dust than any other cyclone technology. To get the full story, visit dyson.com/DC47. Two tiers of cyclones capture more microscopic dust than any other.