The Exo Terra Liquid Crystal Thermometer is easy to read and install and can be placed inside or outside the terrarium. The Exo Terra Liquid Crystal Thermometer has a temperature range from 69-105 degrees Fahrenheit. Maintaining the proper temperature and humidity levels in a terrarium is vital for the well-being and health of all reptiles and amphibians. Exo Terra has developed a complete line of terrarium accessories, including the Exo Terra Liquid Crystal Thermometer that will help you monitor and maintain proper temperature and humidity levels for tropical, rainforest and desert environment.