iOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPhone 6s, released on 2018-12-05T18:10:49Z. The update package is 1.38 GB. This is a delta (partial) update that requires 11.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a77b1603d9e0f05ce03b9399664ae653a15e1ecc.zip.