Features: Wide Application: Ideal for use in water or high moisture environment like aquarium terrarium, or vivarium, suitable for different water types such as fresh water, tap water, salty water, marine water and etc. Easy to Read: Comes with a large LCD display that is easy to read clearly. Easy to Setup: Submerge probe with suction cup can easily be set in water. (Submerge probe only, do not submerge thermometer in water) Press ''PWR'' for 3 seconds to power off. Free Extra LR44: 2 PCS LR44 button cell for each thermometer (one for operation, one for spare). Wide Temperature Range: Measure -58Â°F to +158Â°F (-50Â°C to +70Â°C) with accuracy +/- 1Â°C.