iOS 9.9.12.1 (build 16B5089b) is an official Apple over-the-air update for the iPhone X (Global), released on 2018-10-22T17:01:52Z. The update package is 2.55 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 099efec030285fe983e20a60ac39ca6d3cdbb54b.zip.