iOS 11.3 (build 15E5201e) is an official Apple over-the-air update for the iPhone SE, released on 2018-03-05T18:14:02Z. The update package is 293.31 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: 136577187aeeda74f994153a0c475748c3264711.zip.