Thermometer bimetaal min/max

This metal min/max thermometer is suitable for a greenhouse, among other things. This is because you can see exactly how hot it is at that moment, but you can also see how cold or hot it has been. By looking at the red arrows. To begin with, turn the red arrows toward the black (temperature it is at that moment). Once the temperature drops, one red arrow stays at the highest temperature measured, and the other red arrow shows the lowest temperature measured.