Reptology Life Science Humidity & Temperature Sensors help you track the relative humidity & temperature in your pet's tropical environment. This combo pack gives you the two most important sensors for tracking your reptile's environment. Each sensor has an easy-to-read analog dial that will accurately measure the conditions of your reptile tank. The hygrometer measures relative humidity from 0% to 100% while the temperature gauge provides readings for both Fahrenheit and Celsius in ranges from 0º-110º F and -20º to 45º C. A must for any reptile environment, these gauges are easily mounted using the self-adhesive backings. Each gauge measures approximately 2" x 2" x 1/2" thick.