iOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2016-01-19T17:59:49Z. The update package is 292.3 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: eb17f19d9296a6d7f892dc6b0a725b301c9bff35.zip.