Specifications 

Ambient (receiver unit) temperature range: 0 to + 50
Fridge (remote sensor) temperature range: -40 to +65
Temperature accuracy: +/-1.0
Transmission frequency: 433MHZ
Transmission range: 300 feet (100 meter) in open area
Alarm thermometer : Yes , Both indoor and outdoor
°F /°C: Selectable to degrees Celsius or degrees Fahrenheit
Power requirement(receiver): 2XAAA LR03 batteries Not Included
Power requirement(transmitter): 2XAAA LR03 batteries Not Included