The EHEIM Thermocontrol Aquarium Water Temperature Controller is the best way to keep your underwater companions feeling comfy! It is designed to be waterproof and fully submersible for the most accurate readings. Your aquatic amigos will be sure to appreciate the 0.5°-Celsius control accuracy and precision temperature adjustment from 68° to 89°-Fahrenheit (20 to 32°-Celsius) with no readjustment necessary. A glass coating increases the heating surface to ensure even heat output that’s optimized for both freshwater and saltwater environments. It includes a temperature indicator and double suction holder for your convenience.