iOS 11.0 (build 15A5370a) is an official Apple over-the-air update for the iPhone 6s+, released on 2017-08-31T16:56:18Z. The update package is 36.66 MB. This is a delta (partial) update that requires 11.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6c9850e5c9ff6676b9524667ee9071ea5881ed80.zip.