iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone SE, released on 2018-03-29T17:13:09Z. The update package is 1.27 GB. This is a delta (partial) update that requires 10.3.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1a4d8ad3056233fa3a62a9431670d4706aabf9ca.zip.