Flexible duct HVAC diffusers provide versatility during installation. The diffusers attach to flex duct, which can be easily adjusted in complex buildings. These flex ducts are lightweight and versatile, making them ideal for retrofit installations where rigid ducts cannot be used. While being flexible, these diffusers still provide efficient distribution of ventilation air balance, comfort, and proper indoor climate control. Most suitable for residential attics, crawl spaces, or any commercially ventilated spaces with unique architectural structures.