Using this Reptizoo thermo - hygrometer is a breeze. First, insert the included AG10 batteries into the battery box. Then, choose your preferred attachment method - use the pop - out stand on a flat surface, the clip on a terrarium edge, or the suction cups on a smooth surface. After that, power it on and select your desired temperature unit, either Celsius or Fahrenheit. To get accurate readings, place the metal probe in the area where you want to measure the temperature and humidity. When it comes to maintenance, keep the device clean and dry. Avoid exposing it to extreme temperatures or moisture. If the readings seem off, check the batteries and replace them if needed. Make sure to store the device in a safe place when not in use.