Oregon Scientific THN132N Wireless Temperature Sensor is a low-cost sensor with a water-resistant casing and a battery cover that's easy to slip on and off. Can be set to one of three different channels. Red LED light notifies when data transmission has been sent.
Transmits up to 100 feet from main unit (unobstructed)
Outdoor range : -22 to 140 degrees Fahrenheit (with Lithium batteries)
Outdoor range : -4 to 140 degrees Fahrenheit (with Alkaline batteries)