iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone X (Global), released on 2018-04-24T17:09:29Z. The update package is 822.24 MB. 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: 00e8b6a2fee74a8b9bc0169b86ac4b287b2545f9.zip.