Selectable airflow settings: 110/130/150 CFM (52/61/71 L/s) Virtually Silent operation: 0.5-0.7-0.9 Sones Design - ideal for 2x8 joist construction and taller Energy-efficient, self-compensating DC motor Continuous Flow (available with applicable models) Integrated humidity sensor (available with applicable models) Integrated occupancy sensor (on the SC110-130- 150LHO only) Time Delay (available with applicable models) Ceiling Radiation Damper - bathfan Select (S) Series to be used with the UL555C Fantech Ceiling Radiation Damper-Large (Model #: 98600, sold separately) or the UL555C Fantech Select Radiation Damper (Model #: 494046, sold separately). Includes an 11W, 4000K cool white LED lighted grille (on applicable models only) Built-in, soft-close backdraft damper Adjustable EZ Mounting Frame included Duct connector included: 6" (152mm) For ceiling installations only 5 year limited warranty