Generating Powerful & Straight Airflow - San Ace Counter Rotating Fan - YouTube
Counter Rotating Ventilation Pag Axial Fan for Forward and Reverse Suction - China Pag Axial Fan, HVAC Fan | Made-in-China.com
The contra-rotating fan [16] | Download Scientific Diagram
My most powerful Fan I have. This is the Delta GFM0812DU, a counter rotating fan which is insane. It Spins at 13800rpm in the front (Intake) and 13200rpm in the back. i