Carbon fiber filaments.
The brush bars of most vacuum cleaners only have nylon bristles. These work well on carpets but are not as effective on hard floors where fine dust can be left behind.
The DC44 Animal brush bar has both stiff nylon bristles and anti-static carbon fiber filaments. On hard floors the carbon fiber filaments remove fine dust, and on carpets the nylon bristles remove ground-in dirt.
Carbon fiber filaments
Ultra-fine anti-static carbon fiber filaments clean hard floors.
Stiff nylon brushes remove ground-in dirt from carpets.
Comparison image based on actual results from internal testing and is computer-generated.