iOS 12.1.2 (build 16C101) is an official Apple over-the-air update for the iPhone 6s, released on 2018-12-17T21:06:58Z. The update package is 1.34 GB. This is a delta (partial) update that requires 11.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: efb58e39be2a8184ae35621addf0370b14f78fce.zip.