It is thick and 20 centimeters long, no relation to all those classic thermometers I knew, very ugly to look at inside the refrigerator and its hook could have had more space because it doesn't stand nicely or turn easily.
The worst part is that the blue indication of the scale (like in all similar ones) is NOT VISIBLE when it goes below approximately 15 degrees Celsius because the paper line next to it is exactly the same blue color!
To read the indication, you have to take it out (as I said, the hook is not convenient), clean its surface, and after a few seconds, manage to distinguish between blue-blue the temperature that in the meantime has increased by 2 degrees Celsius.
Pure factory mistake, I solved it myself and put a tape so now it contrasts with the blue inside the tube and you can easily read the indication.
I regret buying it because since I frequently check the freezing, it troubles me a lot in reading it.

As a first impression, it seems to work correctly. In my opinion, since it is made with mercury or some other equivalent material, and since mercury has been abolished, it will have accurate measurements. The measurement is not immediate, it takes a little time, minutes to show the temperature. I have it for monitoring the temperature in the refrigerator because it had some issues recently. I believe it is worth its money.