iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 6, released on 2019-01-22T18:10:31Z. The update package is 215.03 MB. This is a delta (partial) update that requires 12.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ca35ed0cd752a64d7b613e0155677953f6e436b2.zip.