I have never understood why everyone with reptiles uses Acurite. Everyone is so anal about husbandry but they use the worst temp/hygo they can get. The problem is these are cheap hygros and they are in no way accurate and can not be calibrated. These Hygros can be as much as 10% off either way. Spend $25 and get two Xikar or Hygroset and a $5.00 calibration kit. I have put one on each side of my tank and compared it to the Accurite is pretty bad. Cigar people are extremely obsessive about their RH. If you really want to know what the RH is in your enclosures, get an accurate hygrometer.