Oregon Scientific EM221 App Empowered Sensor on Smartphone's & Tablet's for Weather + Via Bluetooth Indoor/Outdoor, White Monitor your local environment. This weather + sensor provides live data of indoor/outdoor temperature to stay connected with Bluetooth up to 90 feet and app notification alerts on your smart device Real time alerts - Bluetooth range is 90 feet and when the temp data is Outside your desired comfort level (Min/Max) setting you will Receive an alert on your smart device. Customize your app Includes a data logger. This EM221 weather sensor can store data for up 20 days, automatically connecting to your smart device when in range. About 90 feet with Bluetooth Multiple locations - up to 20 sensors can be connected to your device allowing you to monitor your whole home or business both indoor and outdoor. -4 F to + 140 F