WhisperSense DC fan with dual sensor capability, motion sensor, humidity sensor, adjustable delay timer, Pick-A-Flow™ Speed Selector 50, 80 or 110 CFM with ECM Motor, <0.3, <0.3, <0.3 sone, Flex-Z Fast™ installation bracket, Integrated dual 4" or 6" duct adaptor, 7-3/8" housing depth.