iOS 12.1.3 (build 16D5037a) is an official Apple over-the-air update for the iPhone 7 Plus (GSM), released on 2019-01-07T18:07:25Z. The update package is 72.65 MB. This is a delta (partial) update that requires 12.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8e1bbd860ce71448c2f96727d57722c077a157f6.zip.