iOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPhone XS Max (China), released on 2018-12-05T18:10:12Z. The update package is 363.42 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: 4e0789b2f9b8b6349f241e97cebec083fbbb4d8c.zip.