This is a wireless digital freezer thermometer. It can be used in the freezer and also act as a thermometer indoor and outdoor. Its audible alarm can warn you of the exceeded temperature in time. Features: * It can be used in the freezer and act as thermometer indoor and outdoor as well. * The minimum and maximum temperature are displayed on the LED screen and can be reset manually. * With indoor and outdoor audible alarm. When the temperature exceeds your preset minimum and maximum alarm setting, it will make a sound alert. * Includes 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 hanging hole so the display is wall-mountable or stands upright on the tabletop. How to Install: The sensor is equipped with a spring-loaded clip along with a plastic grip to tightly attached to the edge of a shelf. The display is magnet-mountable on a fridge, or use the integrated keyhole for wall mounting. Note: Do not install the reverse battery. Do not put the receiver near metal. Avoid the transmitter directly in the rain. Specification: Material: ABS Update Rate: 10 seconds Indoor Temperature Range: 0-50 (32-122) Outdoor Temperature Range: -40-60 (-40-140) Power Supply: 2 * AAA battery for the host (Not included), 2 * AAA battery for the sensor (Not included) Color: White Host Size: 10.0*8.5*2.0cm/3.94*3.35*0.79in Host Weight: 100g/3.52oz Sensor Size: 10.5*3.5*3.0cm/4.13*1.38*1.18in Sensor Weight: 39g/1.36oz Package List: 1 * Host 1/2 * Sensor (Optional) 1 * User Manual