Quiet Air Flow: This ventilation fan operates quietly at 1.1 sones Long Life, Guaranteed: Panasonic ventilation fans use less energy to move larger volumes of air; Less energy leads to less overheating and motor failure, saving you on repair costs; Included 3-year limited warranty Easy-To-Install: Designed for when ceiling ventilation is not possible, this fan woks with 8" ducts and includes mounting hardware Clean Air: Panasonic ventilation fans will increase your air quality, eliminating humidity, mold, mildew, and other air pollutants from any room Code Compliant: This product is ENERGY STAR certified and complies with ASHRAE 62.2, LEED, IAP, CA Title 24, and WA state code