American Aldes OSG Occupancy-Sensing Grille is a stand-alone terminal that automatically boosts the exhaust airflow when a room is occupied. A lens detects movement and triggers circuit opening (instantaneous) and closing (after a 20-minute time out). During installation, the grille is manually set for a boost flow rate of 15, 30, 45, or 60 CFM. The minimum airflow rate is 3-5 CFM when the space is unoccupied. The OSG is powered by 12 VAC current or a 9V DC battery. Some of the most popular applications include hotel and apartment bath exhaust systems.