iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-05-29T17:16:38Z. The update package is 1.46 GB. This is a delta (partial) update that requires 10.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e08bbe0f967627a046e6ae50e82d2f9df1f7b952.zip.