iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 6s, released on 2018-05-29T17:16:31Z. The update package is 683.54 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: a379f8dba9f27270d4e576256060967b78b3b0ca.zip.