iOS 11.1.1 (build 15B150) is an official Apple over-the-air update for the iPhone 6s+, released on 2017-11-09T18:11:08Z. The update package is 1.28 GB. This is a delta (partial) update that requires 10.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 45566269f48b27631132562c8574515952826402.zip.