VEVOR 14 inch Shutter Exhaust Fan, Wall Mounted Attic Vent Fan with Smart Programming Variable Speed Temperature Control, 2000 CFM,EC Motor,Timer, for Shed,Garage,Greenhouse Ventilation Cooling,Black
If only 1 fan can be controlled by the controller, then why does it have 1 hole for the temp and humidity sensor, and 2 holes called 1 & 2 for the controller cable?