Review on Digital Refrigerator Freezer Thermometer with Max Min Record Function and Large LCD Display - Waterproof Fridge Room Thermometer for Accuracy and Convenience (3) by Lisa Golden

Out of the box. All I had to do was press the power button. Let them stand on my desk for about 15 minutes to get a stable temperature, and between the three, the difference in measured temperature was less than 0.3 degrees Fahrenheit, such as 72.3, 72.1 and 72.4 . Put them in the freezer last night to see how the high/low function works. I'll be adding more after a few days of use, but so far I'm impressed!