Revolution 150 Stratos AC — 6" Silenced V2 FanRevolution 150 Stratos AC 6" Silenced V2 Sound Absorbing Fan The ultimate sound absorbing fan Revolution's Silenced V2 raises the bar with a sealed housing that incorporates purpose developed sound reducing foam around silent motors with double balanced blades. A team of engineers developed the novel airflow noise reduction approach that makes this the quietest extractor in its class. Stratos AC variant for growers using standard AC control. Why