iOS 11.0 (build 15A5370a) is an official Apple over-the-air update for the iPhone 6s, released on 2017-08-31T16:56:17Z. The update package is 36.51 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: 50447b617c8c451cdffb4916bfd15507f2e5d4e2.zip.