iOS 11.3 (build 15E5211a) is an official Apple over-the-air update for the iPhone SE, released on 2018-03-12T17:05:49Z. The update package is 220.49 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 62423c61679a1117296ff555175e61899dfed1b2.zip.