iOS 11.1 (build 15B93) is an official Apple over-the-air update for the iPhone 6s+, released on 2017-10-23T17:07:56Z. The update package is 241.67 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: 6637070fef5ff39f46357fddd1b0c02603b7d12c.zip.