Hydrofarm AutoPilot Analog Garden Temp Co2 Environmental Controller w/Sensor APCETHA Autopilot Analog Enviromental Controller Coordinates supplemental CO2 with your ventilation equipment CO2 outlets are automatically disabled while your ventilation equipment is functioning 15' Remote probe with highly accurate sensor Mode 1 - Temperature and dehumidifier split. Lowers the temperature and decreases humidity independently. Thermostat activates cooling output and humistat activates dehumidifier output.