The "RolloTron Comfort DuoFern" is an electronic belt winder for flush mounting and can be used universally, as it fits into any standard belt box with a width of 36 mm or more. It is characterized by quick and easy installation. Installation and commissioning take about 10 minutes. Operation is via Euro plug connection to the 230 V power supply. It is the successor to the Comfort DuoFern model from RADEMACHER's 9800 series. The new "RolloTron Comfort DuoFern" appears in a modern design with a large, illuminated display with contrast adjustment. It features an installation wizard and has an integrated interface for quick and easy integration into the DuoFern radio system. It can be remotely controlled by DuoFern transmitters. Used as a central controller, it can send automatic commands to the registered DuoFern receivers. It has extensive automatic functions such as the day, week, weekend and astro program and the random function. The ventilation and sun position can be freely selected. Also a simple approach of intermediate positions is possible. The summer/winter time changeover is automatic and a key lock can be set to prevent unintentional operation. The soft-start/soft-stop function enables smooth running with a high level of comfort. Sun/twilight control is possible with the S/D sensor available as an accessory.