The Onset MX2203 HOBO TidbiT MX Temperature and Water Temperature (400 ft.) Data Logger measures temperature in streams, lakes, oceans, coastal habitats, and soil environments. Housed in a protective boot, this rugged logger is designed for extended deployments in fresh or salt water, at depths of up to 400 ft. The logger uses Bluetooth Low Energy for wireless communication with a mobile device and is equipped with an optional water detection feature that automatically turns Bluetooth advertising off when the logger is submerged in water, thereby preserving battery power. Using the HOBOmobile app, you can easily configure the MX-2203, download logged data to your phone or tablet, or automatically upload the data to HOBOlink for further analysis. You can also configure this device to calculate statistics, set up alarms to trip at specific thresholds, or enable burst logging in which data is logged at a faster interval when sensor readings are above or below certain limits.