SunSun WDJ-005 Digital LCD Thermometer For Aquarium Waterproof thermometer with LCD display Equipped with a mounting suction cup for easy installation of the device inside the aquarium. The small thermometer can be set anywhere, even under water, so that the temperature reading, with an accuracy of 0.1 degree C, will be much more convenient. The kit includes batteries: LR44 � 1.5V