watchOS 5.1.2 (build 16S6046) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2018-12-06T18:04:53Z. The update package is 76.25 MB. This is a delta (partial) update that requires 5.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c396caa4aa9713d0cf354f49d6f773b6ce90204e.zip.