With the 12 power levels available from the Dc motor, this fan is perfect for any environment. At levels 1-4 the fan operates silently (below 35dB). Levels 8-12 circulate the air most powerfully. Detects the room temperature and adjust the fan level automatically while in Auto mode. Decrease the air flow gradually over 2 hours before turning off in Sleep mode, and alternates between low and high power to simulate natural wind while set to Rhythm mode. 360-degree vertical oscillation and 90-degree horizontal. The unique oscillating motion covers a wider range in the room and contributes to better air circulation throughout the environment. Place the unit by the window or entrance to a room to regulate the air quality. Face the fan outside to air out the room or face the fan inside to pull in fresh air from outside.Dimensions: 12.6"L x 12.6"W x 40"H