This simple pair of mercury thermometers, priced at just £2.95, look identical but have different scales, one for the fridge and the other for the freezer. The scale is colour coded to indicate if the temperature is too hold, cold or within the target zone for the appliance.
Although each of the 14.5cm x 2cm x 0.7cm thermometers is made from plastic the build quality seems fine and they seem perfectly robust enough for daily use. They have hooks so they can be suspended within the fridge or freezer which may give a more accurate reading than when laid flat.
In use, they work well enough but can be rather difficult to read as they have to be held at an angle to read the mercury and this is doubly difficult with the freezer one which I found has a tendency to frost over the mercury glass. That aside, they could not be easier to use and are fine for the purpose intended. If a more accurate reading is needed then more expensive rivals are available. Models using a bimetallic strip should be easier to read but avoid battery-operated models as battery life will be restricted when left in the freezer over time.
This is a perfectly good buy for home or non-critical use and the price certainly cannot be bettered.