• Digital Thermometer Can be installed anywhere inside of fish tank wall through the built-in suction cup• Can be placed up to 30cm underwater indicating the tank's temperature to be adjusted according to the living conditions of the fish• LCD Display Screen clearly shows the inside temperature in the fish tank• Temperature Range: Working Temperature 0 ? 70 °C, Working Range 0 ? 50 °C• Power Supply LR44 Battery (not included)