iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2019-01-22T18:14:21Z. The update package is 505.1 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: e61aba3d7f0d3b7e1ed6c5b690a4c59e23c78a0a.zip.