iOS 12.1 (build 16B5084a) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-10-15T17:03:27Z. The update package is 417.28 MB. This is a delta (partial) update that requires 12.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a05c74796ce2f253f8ad0d9f81160579197496bd.zip.