iOS 11.4.1 (build 15G77) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-07-09T17:10:24Z. The update package is 793.59 MB. This is a delta (partial) update that requires 11.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c9661d82be22ab10b7093c6b2f208cd815872464.zip.