watchOS 5.1.2 (build 16S46) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2018-12-06T18:03:59Z. The update package is 430.1 MB. This is a delta (partial) update that requires 5.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 26f5fdc5957d259cd13c2bde1935275ef1fa1dbe.zip.