iOS 11.4.1 (build 15G77) is an official Apple over-the-air update for the iPhone 6s, released on 2018-07-09T17:10:07Z. The update package is 1.34 GB. This is a delta (partial) update that requires 10.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1e120b6422998be45ee80250fc042e37ab5b92b0.zip.