iOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2017-12-13T18:14:52Z. The update package is 1.19 GB. This is a delta (partial) update that requires 10.0.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ed40cb997c28f60b5c23fb9e0c60efaaa66e8539.zip.