CO2 Controller Model # 2002B by Control Wizard. This unit was manufactured to connect to the Control Wizard CO2 Monitor Model # 2002A.This unit is designed to turn CO2 equipment ON and OFF at preset levels by computing the Monitors signal output. Simply plug in your CO2 equipment in the outlet provided. Then, plug one of its power cords into a wall outlet and the other cord into a controlled power outlet (like you would find on any brand of atmospheric controller) that powers your exhaust fans. When the exhaust fans are powered the Controller will automatically turn your CO2 equipment OFF. This saves CO2 from being vented while the area is being cooled. When the exhaust fans shut OFF the CO2 equipment is allowed to fill the room to your pre-set levels.