The Fluke BT521ANG is a Bluetooth Low Energy (BLE) temperature sensor that can be used with the Fluke Connect mobile app to monitor temperature remotely. The sensor has a range of -40 to 125°C (-40 to 257°F) and an accuracy of ±0.5°C (±0.9°F). It is IP67-rated for water and dust resistance and has a battery life of up to 2 years.