iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone X (Global), released on 2019-01-22T18:08:46Z. The update package is 1.65 GB. This is a delta (partial) update that requires 11.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8f27160538b3b3113fce1b79e6cd4149bb95b80a.zip.