iOS 11.1.1 (build 15B150) is an official Apple over-the-air update for the iPhone 6s+, released on 2017-11-09T18:11:12Z. The update package is 40.71 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 43e3557021bfd2e45248b30870635b1124c995d7.zip.