iOS 9.2.1 (build 13D14) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2016-01-04T17:58:50Z. The update package is 32.76 MB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6ccec1376bb08c2b0216424cf8ee8a7ac48a4539.zip.