iOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone SE, released on 2018-04-24T17:11:13Z. The update package is 761.91 MB. This is a delta (partial) update that requires 11.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 776bc92be2c5a33ac4d04da069a0b469c44f213a.zip.