iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone 7 (Global), released on 2018-04-24T17:11:24Z. The update package is 35.22 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: abe1f1505704b27402ad8c3ba272d6865736ecde.zip.