watchOS 5.1.2 (build 16S46) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-12-06T18:04:35Z. The update package is 764.64 MB. This is a delta (partial) update that requires 4.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 77b5c3c5310c0eefa573c128641700399c5838d5.zip.