iOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPhone 6s+, released on 2015-10-21T17:16:06Z. The update package is 313.49 MB. This is a delta (partial) update that requires 9.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7a9e41b6c9c0e11c5c02be8deebe8e7bdda65f8d.zip.