iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone 7 (Global), released on 2018-04-24T17:11:22Z. The update package is 842.01 MB. This is a delta (partial) update that requires 11.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e84b5b82eff1a479aa747933118abdd518810c74.zip.