La Crosse Technology TX141TH-BV2 Wireless Outdoor Thermo-Hygrometer Compatible with models 308-1414B, 308-1414w, 308-1414MB, 308-1425B, 308-1425c, S87078 and S88907 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) Note : Mount the temperature/humidity sensor on a north-facing wall or in any well shaded location. Sun will make it read high. Under an eave or deck rail is preferred. Be sure the outdoor sensor is mounted vertically to drain moisture. The maximum wireless transmission range to the weather station is over 300 feet (91 meters) in open air, not including walls or floors 433MHz frequency Detects Temperature and humidity Red LED light will flash when transmission occurs Temperature range: -40 F to 140 F (-40 C to 60 C) Humidity range: 10 to 99% RH Update interval: About every 58 seconds Wireless, battery operation Weather-resistant, not waterproof Recommended sheltered from extreme weather, such as: constant precipitation, direct sunlight To Position your sensor: Mount sensor outdoors on a North-facing wall well shaded area; 18 inches under eaves; deck railing are preferred locations Mount sensor in vertical position to drain moisture Maximum transmitting range is up to 300 ft (91m) in open air (walls, floors, windows can reduce range) Powered by 2-AA batteries (not included) Optional to use alkaline or lithium batteries Recommend using batteries: Expiration date 6 years in advance of current year or 1.48v read on voltmeter; good brand name (reduces RF interference)