iOS 9.9.10.3 (build 14E277) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2017-03-27T16:57:34Z. The update package is 1.24 GB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b740d2419532eff4f44d7f29b0e2f6be8a81a9d3.zip.