Zoo Med's Precision Analog Gauges are of professional breeder quality, with many features not found in cheap imported gauges. Features include European-made precision German movement, side-venting to prevent against "fogging" inside the thermometer, and Velcro backing enabling you to remove the gauge for terrarium cleaning and maintenance. Allows for the monitoring of temperature and humidity of your terrarium with one unit. Thermometer scale 20F-120F (-6C to 49C). Humidity scale 0 to 100%