iOS 12.1.1 (build 16C5036c) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-10-31T17:03:59Z. The update package is 287.01 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fb1f914765173443c41d85ce84795fde3904ed79.zip.