iOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPhone 6, released on 2016-01-19T18:20:42Z. The update package is 302.97 MB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b0f6ffb2ee71002fcf0971f6ebae271f917fe3ba.zip.