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 1.43 GB. This is a delta (partial) update that requires null already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 3f3c42a136b02c637f758673ad9bd9de51c5806a.zip.