MK2 Twin Fan Controller Pro expandable environment control The Twin Controller Pro is software controlled with MOTION FLOW. Therefore, it reacts completely differently to the usual controllers. The Twin Controller Pro makes an evaluation for the gradual increase or decrease of your fans. By altering the fan speed the controller will automatically find the appropriate ventilation level at which the programmed temperature is maintained. This new technique means no more temperature fluctuations and fan noise is kept to a minimum. In addition, the PRO software on the Twin Controller Pro will also keep humidity in your room under control during the dark cycle – when it matters the most!