Premium Bath fan 110 is energy efficient and great for clearing the air in smaller rooms with a grill that mounts in the ceiling while the fan motor mounts in a remote location away from the living area, resulting in quiet yet powerful ventilation. Grill housing and damper uses a 4 inch duct. Hanger bars extend to 24 inches OC and set screw locks bars into position. Key hole mounting slots. 110 airflow (CFM) at .02sp for a 100 sq ft room. UL listed for wet locations. IC rated. 7 inch diameter x 4 inch height.