Most tropical fish have specific temperature requirements in order to thrive. The Penn-Plax AquaLIFE Therma-Temp Digital Aquarium Thermometer makes it easy to know exactly what temperature your aquarium is at. This thermometer mounts conveniently on the outside wall of your aquarium with a pressure-sensitive backing. The numbers are clear and easy to read as the green color shows the correct temperature.
INSTRUCTIONS: Green color shows the correct temperature of the water.