WhisperSense 110 CFM Ceiling Mounted Ventilation Fan with Dual and Humidity Sensor Technology Air Movement (CFM): 110 Mounting Opening: 10-1/2-Inch by 10-1/2-Inch Sound (sones): &lt; .03 Grille Size: 13-Inch by 13-Inch Humity switch adjustable from 30-80-Percent