The Ranco® RDTB(Button) & RDT(Soft Touch) Series Digital Controller are new generation microprocessor-based, multi-function, configurable temperature controls for commercial refrigeration applications, such as freezing and refrigerating display cases and compartments, coolers and chillers, and plug-in refrigerated counters. They provide for full control of ‘static’ or ‘ventilated’ refrigeration units working at positive and negative temperatures, and incorporate all features needed by modern systems for complete compressor and evaporator fan management, as well as defrost control. All models can be chosen heat or cool mode and come together with NTC thermistor sensor for cooling application only (-50ºC to +50ºC)