The device is very good, made by the leader in the field of medical electronics. However, I grant it 3 stars because of a complex or random operation. Indeed, after applying ten times the maneuver described in the manual to switch off, it remains on and displays the room temperature. Or the unit is defective, or the manual is incomplete. I would tend to incomplete manual that should show a screen display when turned off. What is certain is that with a continuous display the CR2032 coin cell battery will not last long. And, of course, is when the user needs it he will find that the battery is empty. This device is still a reference in its domain, but I recommend to become familiar with its use before purchasing, try asking in a pharmacy, for example.