iOS 12.1.2 (build 16C101) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-12-17T21:07:04Z. The update package is 1.83 GB. This is a delta (partial) update that requires 10.3.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1c21c0625e1e9156d6d86e9ac2d846f9ee7c80f6.zip.