iOS 10.2.1 (build 14D27) is an official Apple over-the-air update for the iPhone 6s, released on 2017-01-23T18:08:36Z. The update package is 345.37 MB. This is a delta (partial) update that requires 10.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 32dae923f87d765c8c5d68d609f7a8dc6cf6a47a.zip.