iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone 7 (Global), released on 2018-04-24T17:11:23Z. The update package is 737.8 MB. This is a delta (partial) update that requires 11.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ce183df80c2e0c7db7580ce7cf4eb39b8e5e92aa.zip.