iOS 11.4 (build 15F5049c) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-04-16T17:08:15Z. The update package is 206.46 MB. This is a delta (partial) update that requires 11.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6ace046ae68841564e42eaaea29a0c7b7504239e.zip.