iOS 12.1.2 (build 16C101) is an official Apple over-the-air update for the iPhone 6+, released on 2018-12-17T21:06:46Z. The update package is 403.16 MB. This is a delta (partial) update that requires 12.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 89cf86ed0e219386c95bcdc16684651db1c0486f.zip.