iOS 10.3 (build 14E5273a) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2017-03-13T17:01:25Z. The update package is 256.19 MB. This is a delta (partial) update that requires 10.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 489679c0933744ff175516af58f38378352fe088.zip.