Topunion Digital Electronic Freezer Refrigerator Thermometer with Magnet and Clip Stand High Low Temperature Alarm Thermometer Wall Type LCD Digital Refrigerator Thermometer with Sensor LCD Freezer Thermometer Displays Measured Temperature Value. Easy to Read Magnet on Back: Easy to be Absorbed on the Smooth Surface. Mounts on the outside of your refrigerator easy-to-view LCD display Thermometer Working Range: -20~70C (-4~158F); Sensor Cable Measurement Range: -50~70C (-58~158F) ROOM/FRIDGE Key: Inner and Outer Temperature Conversion (Must insert sensor cable) ALERT Key: Temperature Alarm Set, on/off Temperature Alarming Function as Pressing Quickly. It has a Maximum/Minimum Temperature Memory, Two Alarm Settings (High/Low Temp Alert) and Features a Audible Alarm.