iOS 11.4.1 (build 15G5054c) is an official Apple over-the-air update for the iPhone 6s, released on 2018-05-30T17:05:16Z. The update package is 221.2 MB. This is a delta (partial) update that requires 11.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 25e05fdf95111e2d37c1c9bbaa22571ad276e257.zip.