iOS 9.1 (build 13B5119e) is an official Apple over-the-air update for the iPhone 6s, released on 2015-09-23T17:55:10Z. The update package is 195.57 MB. This is a delta (partial) update that requires 9.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 26a8f964e8e20d19dc5947deb1bf1f36bcf1f6c7.zip.