iOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPhone 6+, released on 2016-01-19T18:20:40Z. The update package is 265.23 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: 336b64dbdc695eb6ec375fc00dd7123fb142ffd8.zip.