Single whisper-quiet fan for spot cooling mounts to notches in vents on specified Lowell racks. Kit for single 4.7” [119mm] diameter fan with 50cfm airflow rating and quiet 28dBA noise rating is great for spot cooling. The cast aluminum housing is 4.7” square x 1.5”D [120mm square x 38mm]. It includes a fan guard and cord - standard black or green “thermo-cord” which has an integral thermostat to control fan operation. The thermostat automatically turns fans on when the ambient temperature reaches 86°?F [30°C] and off when the temperature reaches 72°F [22°C]. This power saving feature ensures efficient operation while saving wear and tear on the unit.