iOS 12.1 (build 16B5077c) is an official Apple over-the-air update for the iPhone 6s, released on 2018-10-09T17:05:59Z. The update package is 274.32 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: 2d8b17840cf99ed2baa5563dfb87a6de5e1c49d3.zip.