iOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPhone X (GSM), released on 2018-12-05T18:10:10Z. The update package is 1.54 GB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6c8c39f1fd7670dc4049429027b1dceccef71a73.zip.