The Digital easy read thermometer is used inside the aquarium.
Simply place the easy read thermometer into your aquarium and use the suction cups provided to stick the thermometer on the inside of your tank.

Technical parameters:
Temperature. measuring range:-50 to +70celsius (-58to +158fahrenheit)
Resolution: more than -20celsius is 0.1
lower than -20celsius is 1
Accuracy:±1celsius
Power: DC1.5V button battery (Supplied)