iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 6, released on 2018-05-29T17:16:20Z. The update package is 683.35 MB. This is a delta (partial) update that requires 11.2.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 149f9a78594afdca2fd0c2abf427092d2806ad31.zip.