Master Controller ECM1For our EL2 controllers we developed an External Contactor Module, the ECM1. As the Master Controller works on a low voltage output, it is not capable of switching auxiliary equipment. With the ECM1 you can extend the functionality of your EL2 controller to switch auxiliary equipment, such as heaters, dehumidifiers and CO2 equipment during the lights on or lights off cycle, according to the controller set lighting hours. Specifications ECM Voltage 120