A revolutionary series of vent fans that combine energy efficiency, ultra-quiet operation and a collection of advanced technologies that deliver unparalleled performance. An extremely energy efficient DC motor powers the patented TechnoFlow™ system. Noise is reduced to levels that were previously thought to be unattainable. In addition, the DC motor provides the capability for a range of new features including SmartFlow™ technology, CustomVent™ variable speed control and an available SmartAction® motion sensor.