I had a mercury thermometer was not very accurate and that was a little toy ... so it was hard to make me an idea of the temperature of the fridge and freezer, I saw this product on this site and I thought that digital would be more appropriate for me who really wanted to keep my food and I had a hard time getting there.
This product is very good, small but with a big enough display that fact that we can see just by opening the door to take a food, it goes everywhere, and I find the reliable, that extra temperatures + and - I'm using little but it's interesting nonetheless.