watchOS 5.1.2 (build 16S5046a) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-11-15T18:08:51Z. The update package is 124.87 MB. This is a delta (partial) update that requires 5.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: adc9a2b1c5b0044053f2a6a8b796b27e2ceaa299.zip.