iOS 12.1 (build 16B5089b) is an official Apple over-the-air update for the iPhone X (GSM), released on 2018-10-22T17:01:57Z. The update package is 193.21 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: d4c93c7a8440c487bf7ba1cc7350fe40e3992aff.zip.