Steps to use: First press the PWR button on the aquarium thermometer; then put the sensor probe into the water; the suction cup attached can stick the LCD screen to the side of the aquarium. Easy to read: You can easily read the water temperature through the LCD screen of the aquarium thermometer. The temperature unit can be switched between C and F with the button. Measurement range: The measurement range of the aquarium thermometer is -50C ~ +70C / -58F ~ 158F, accuracy is +/- 1 degree Celsius. Dimensions: 583815mm. Power supply: LR44 battery (included). Wide application: Thlevel aquarium thermometer is suitable for aquariums, aquariums, reptile boxes, incubators, refrigerators, cigar houses, etc. It can protect reptiles, fish and small animals from dangerous temperatures. Package includes:You get 2 aquarium thermometers, each with 1 LR44, 1.5V button battery and 2 suction cups. Probe cable length: 1 meter. NOTE: Do not put the thermometer into water, only the probe sensor is waterproof. Note: The picture is for reference only, please refer to the actual product, thank you. ! ! Product name: Aquarium Thermometer. Material: Plastic Colour: Black Dimensions: approx. 58 x 38 x 15 mm Weight: approx. 70g Package content: set of 2 pieces.