iOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPhone 6+, released on 2015-10-21T17:16:04Z. The update package is 1.19 GB. This is a delta (partial) update that requires 8.4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 18ad88294fd6e43ad05ce48d01db3779df9774c5.zip.