iOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPhone 5s (Global), released on 2018-10-30T17:16:35Z. The update package is 1.69 GB. This is a delta (partial) update that requires 10.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 747746799f01fd1fbbdc82d9983ddc93622d57b0.zip.