MOKOQI Professional Digital LCD Aquarium Thermometer for Hydroponics & Aquaculture, Amphibian & Reptile Terrariums, Freshwater Tropical Fish & Saltwater Fish Aquariums SENSITIVE DESIGN:Aquarium digital thermometers for terrariums with Fahrenheit and Celsius LCD display and suction cup for mounting external sensor probe inside or outside of the terrarium. External Sensor can be mounted in dry or wet area of terrarium. EASY TO USE: Accurately measure air and water temperatures thermometer up to +/- one degree. Easy to use selectable fahrenheit/celsius switch with large easy to read display. To turn on press and hold the power (pwr) button. To turn off hold the power button for 5 seconds. NOTE: Simply submerge probe into fish tank to measure water temperature.Includes 2 2.5-cm suction cups for attaching the digital reptile thermometer to the outside of the aquarium. GOOD FOR PETS: Protects reptiles, fish and small animals against unsafe temperatures. Uses one LR44, 1.5v battery (included). Suction cup included. Consider these other items: terrariums, aquariums, reptile heaters, basking lamps, heat emitters, mercury vapor lamps, hydroponics & aquaculture. PERFECT FOR AQUARIUM: Ideal for aquariums & reptile habitats. For use with both freshwater & marine aquariums, and great for monitoring temperatures in reptile & amphibian terrariums, and small animal habitats.