The update was released only for iPhone XR.
Apple has unexpectedly released an updated version of iOS 12.1, however, the firmware has only been available for iPhone XR. In the description of the updates is not specified, the list of innovations, but it is obvious that the updated build of iOS 12.1 number 16B94 contains fixes for iPhone XR. IPhone users XR can install updated iOS version 12.1 over the air or via iTunes.
Apple did not specify what changes have occurred in the new Assembly for iPhone iOS 12.1 XR. It is noteworthy that iPhone users XR is not stated about any massive bugs, so what fixes the update is unknown.
However, all users iPhone XR it is recommended to install a new version of iOS 12.1. This can be done in the menu “Settings” → “Main” → “Update” or downloading the update via iTunes.