Exo Terra Rept-O-Meter Thermometer The Hagen Exo Terra Rept-O-Meter Thermometer measures your terrarium temperature in Fahrenheit and Celsius to ensure reptiles are kept safe and comfortable. It mounts easily on smooth surfaces, is accurate and has an easy to read colour-based display. Monitors terrarium temperature levels Easy to read in Fahrenheit & Celsius Mounts easily on smooth surfaces