If you buy the ones with gauges you just as well throw your $$$ in a trash can as they are A JOKE!!! Get the ones with a probe for inside the cage or for your Cham room get a Accurite from Walmart for under $10.00 with tax and it shows current temp and humidity as well as a 24 hour high and low for both. I will post a picture in my next post. I have checked the Accurite with multiple other forms of temp monitoring including a $80.00 laser temp gun and they have all been within 1-2 degrees of each other.