iOS 11.4 (build 15F5061d) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-05-01T17:06:01Z. The update package is 181.46 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: 5b8cc8c70c8e73e1474cb2813b5cf71ae2de8502.zip.