iOS 10.2.1 (build 14D27) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2017-01-12T21:12:00Z. The update package is 29.43 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: 396323e7bc8a9ef45be59efb2ed21a1839fb4021.zip.