This Floating Glass Thermometer is designed to float in the water in a vertical position. It comes with a suction cup for installation on your aquarium glass.
For fresh or saltwater aquariums.
Accurate and easy to read – provides temperature readings in Centigrade and Fahrenheit.
It also has a safety zone temperature range indicator for most tropical fish.  Water temperature is a critical factor for the well-being of fish, so it’s important to have a good thermometer.