iOS 11.4 (build 15F5049c) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2018-04-16T17:08:29Z. The update package is 273.3 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: d518c15ebc8c977f280708cc06183218f606f168.zip.