Waterproof Design:With a sealed ring design, the fish tank thermometer can be completely submerged in water for more accurate water temperature measurement. LCD Display:You can easily read the temperature through the LCD display of the aquarium thermometer. The measuring range of fish tank thermometer is 0C~50C. Powered by a LR44 battery. (Battery is included) With Suction Cup:Simply find the best position in the tank and use the small suction cups to fix it in the tank. The suction is strong enough to keep the thermometer in place at all times. No Cables:The aquarium themometer works precisely without any external wire and probe, making your tank look clean and tidy and does not obstruct the space for fish to move around. Extreamly Easy To Use:This is the simplest aquarium thermometer on the market and does not require any button operation. Suitable for fish tanks, reptile boxes, incubators, refrigerators, cigar houses, etc.