Wireless Remote Outdoor Sensor, Use with Bluelink Smart Connect Thermostats, Display Outdoor Temperature, Heat Pump Balance Point Control, DC Power:3.0 Volts DC (2AA Lithium Batteries Not Included),with Mounting Bracket,Dims:3-1/4"H X 4"W X 1-1/4"D,Weight:0.35oz. Made In China, Mfg/Box."