iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2018-03-29T17:13:32Z. The update package is 791.16 MB. This is a delta (partial) update that requires 11.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5d19c8bb1fb4710b4307bc956b295a88a0d0038d.zip.