iOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPhone SE, released on 2017-12-13T18:14:06Z. The update package is 1.1 GB. This is a delta (partial) update that requires 10.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 458411d5d5ec2584904e86ab5546abca4e52fcd8.zip.