iOS 11.4 (build 15F5037c) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2018-04-02T17:07:01Z. The update package is 314.04 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: dd8388550e34b8b45f74002c61c94f2fc0fe04fe.zip.