iOS 11.3 (build 15E5189f) is an official Apple over-the-air update for the iPhone SE, released on 2018-02-20T18:06:27Z. The update package is 297.64 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: ef9d1178f1bc2362659ae4d0276a60d6f9818220.zip.