iOS 10.2.1 (build 14D23) is an official Apple over-the-air update for the iPhone 6s, released on 2017-01-09T17:55:56Z. The update package is 60.59 MB. This is a delta (partial) update that requires 10.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9c8dfef5051ee918a970c84efe5f6c212546385f.zip.