This battery-operated Tetra TH aquarium thermometer TH35 is a precise liquid thermometer with a temperature measurement range of 20°C to 35°C. It offers good readability and easy adhesive mounting on the outer wall of the aquarium glass. The correct water temperature in the aquarium is crucial for the well-being of your fish. Since fish cannot regulate their body temperature themselves, many species are susceptible to temperature fluctuations. An inappropriate water temperature can quickly become dangerous or lead to the premature death of the fish.