iOS 12.1 (build 16B5077c) is an official Apple over-the-air update for the iPhone X (GSM), released on 2018-10-09T17:05:44Z. The update package is 325.13 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e70006647ce617db50caf197060c9579969f9526.zip.