Broan RB110 Ultra Pro Series Single-Speed Fan (110 CFM, 0.6 Sones) 110 CFM reduces humidity to quickly eliminate fogged mirrors and manage moisture in bathrooms up to 105 square feet Stream technology - state-of-the-art blower design with airflow-smoothing baffles optimally smoothes airflow and reduce turbulence so the wheel can turn more slowly and quietly with no airflow loss Qf low technology - duct connector damper flap is completely removed from airstream to reduce static pressure again, allowing the blower to turn more slowly and quietly Ultra quick installation technology uses an exclusive telescoping mounting Frame with pre-installed screws, snap-in housing, snap-in blower and an inside-out mounting duct connector Retrofit installations can be done entirely from the room-side  no attic access required