La Crosse Technology TX141TH-B Wireless Outdoor Thermo Hygrometer Transmitting Sensor Compatible with models 308-1412S, 308-1414B, 308-1414MB, 308-1425B & C, 308-1711BL Wireless transmission of 200ft range (open air) Battery powered requires two AA batteries (not included) Measuring range: -40 F to 140 F (-40 C to 60 C) Outdoor humidity: 1% to 99% RH