iOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-12-05T18:10:59Z. The update package is 1.42 GB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d8cbb3e49f26781724048cf55e37d988e9cfe359.zip.