Operating Temperature: -10°C - +50°C Accuracy +/-1°C LCD digital display °C and °F display Water resistant probe High-quality silicone suction cups for easy attachment 90cm cable length Suitable For: Coldwater, Tropical & Marine Operating Instructions Press the FSW button to turn on. Press and hold for 3 seconds to turn off. Using the suction cup provided. Attach the display unit to the outside of the aquarium. Submerge the probe into the water in the aquarium. Do not submerge the display unit. Only the probe is water resistant. To switch between Celsius and Fahrenheit, slide the °C/°F switch.