iOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPhone SE, released on 2018-10-30T17:17:21Z. The update package is 1.37 GB. This is a delta (partial) update that requires 11.0.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d2478bf21445404515604aedee80d61544d7dbfb.zip.