iOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-12-05T18:11:02Z. The update package is 408.58 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: 4cf8d208d3709317a11e225d0a90b9cbd80532a7.zip.