iOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPhone 5s (Global), released on 2016-01-19T17:59:51Z. The update package is 1.1 GB. This is a delta (partial) update that requires 8.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1de098ef33c37237a386e132a6c30572bbdd0a2d.zip.