iOS 11.1.1 (build 15B150) is an official Apple over-the-air update for the iPhone 6s+, released on 2017-11-09T18:11:11Z. The update package is 241.78 MB. This is a delta (partial) update that requires 11.0.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5396fa42e9c610d81dd7c8b8ae77c8c382de497b.zip.