La Crosse Technology TX142THV2 Wireless Outdoor Thermo-Hygrometer Transmitting Sensor Compatible with models 308-1451, 308-1451H, 308-146, 308-146w, 308A-146, and B86012 Wireless transmission of 300ft range (open air) Temperature range: -40 F to 140 F (-40 C to 60 C) Outdoor humidity: 1Percent to 99Percent RH Battery powered Requires two AA batteries (not included)