iOS 12.1.3 (build 16D5032a) is an official Apple over-the-air update for the iPhone 6+, released on 2018-12-19T18:07:01Z. The update package is 226.78 MB. This is a delta (partial) update that requires 12.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8b5facf00d1a52dbd1e80c580460b0f4eee156d3.zip.