iOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2015-10-21T17:16:00Z. The update package is 965.62 MB. This is a delta (partial) update that requires 8.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d56e572e49dab05c247b121956692c213333828e.zip.