iOS 11.4 (build 15F5079a) is an official Apple over-the-air update for the iPhone 6, released on 2018-05-17T17:02:29Z. The update package is 41.96 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: adf389a908248ba41a21c924042721bd5372c677.zip.