Features: The minimum and maximum temperature are display on the LED screen and can be reset manually. With indoor and outdoor audible alarm. When temperature exceed your pre-set minimum and maximum alarm setting, it will make a sound alert. It can be used in the freezer and act as therometer indoor and outdoor. Includes 24 hours Min and Max temperature records and you can easily monitor the temperature change of your refrigerator and provide double protection to your food safety. With a temperature trend indicator arrow and daily high and low information. Comes with a adjustable hook so the dispay is wall-mountable or stands upright for tabletop use. Specification: Material: ABS Update Rate: 10 seconds Indoor Temperature range: 0 ℃ ~ 50 ℃ (32 ℉ ~ 122 ℉) Outdoor Temperature range: -40 ℃ ~ 60 ℃ (-40 ℉ ~ 140 ℉) Power Supply: 2 X AAA battery for the host, 4 X AAA battery for the sensor (Not included) Package Included: 1 x Host (Battery not included) 2 x Sensor (Battery not included) 1 x User Manual Notice: Do not install the reverse battery. Do not put the receiver near metal. Avoid transmitter directly in the rain.