From Mangrove Jack, digital thermostat and probe, pre-assembled and ready to plug in. Dual purpose. Default setting lets you run a fridge or freezer up to the ambient temperature, ie thermostat turns a cooling device when the temperature warms up to the set temperature. Ideal for summer brewing, or brewing lager beers. Change the setting and you can run a heating device, ie the thermostat turns on when the temperature drops to the set temperature.