1.Max/Min Temperature Max/Min temperature data will be updated every 24h. Please note that the product cannot maintain the max/min temperature all the time. 2.Alarm With the sound alarm, you can manually set the maximum and minimum alarm value. It can sound when the temperature value reaches the point of maximum or minimum alarm value you preset. 3. Easy to use There are 6 function keys on the main unit and a signal indicator on the transmitter, you just need to press the corresponding key to turn on/off the alarm, change Celsius or Fahrenheit.< /p> 4.With built-in magnets, hanging hole and bracket on the back, you can put the main unit in the fridge door, hang on the wall or stand on the table. 5.Please install the new battery to ensure the accuracy.