Color as shownSize: 15.7 x 13.5 x 2.1 cm weight:110g First press the PWR button of the aquarium thermometer; then put the sensor probe into the water; The attached suction cup can stick the LCD screen to the side of the fish tank. You can easily read the water temperature through the aquarium thermometer LCD screen. The temperature unit can be switched between °C and °F with the button. The measuring range of the aquarium thermometer is -50°C ~ +70°C / -58°F ~ 158°F, the accuracy is +/- 1 degree Celsius. Power supply: LR44 battery not included Thlevel aquarium thermometer is suitable for aquarium, fish tank, reptile box, incubator, refrigerator, cigar house, etc. It can protect reptiles, fish and small animals from dangerous temperatures. NOTE: Do not immerse the thermometer in water, only the probe sensor is waterproof.