Apple has released iOS 10.0.3 update exclusively for the iPhone 7 and iPhone 7 Plus. The lightweight patch mostly aims to fix a bug that could cause some users to temporarily lose mobile data connectivity. This update is not available for other iOS devices. iOS 10.0.3 is 75.7MB and is now available to download. If you have been facing mobile data issues, make sure you update immediately.
Source: http://www.gsmarena.com/ios_1003_update_released_for_the_iphone_7_and_7_plus-news-21121.php