Innovative Wind Ring air system provides high volume air movement. Save-Smart - Less than 2 cents per hour. Three quiet speeds Durable Steel Body. Two-year limited warranty ETL Listed. Step up to the Premium Box Fan and enjoy the benefits of the Wind Ring System an exclusive grill design that focuses the air movement increasing its velocity. Three Whisper-Quiet Speeds. 30% More Air Velocity than Most Standard Box Fans. Energy-Efficient High Volume Air Movement. Wide-Body Design for Stability. U.L. Listed."