iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone 7 Plus (GSM), released on 2018-04-24T17:11:40Z. The update package is 854.19 MB. This is a delta (partial) update that requires 11.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7a35a9b91aaba430737a9289d55c7c5cc31e6dc3.zip.