watchOS 5.1.2 (build 16S5046a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-11-15T18:09:02Z. The update package is 52.97 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: 051d9c699fd053d41919411f3d7fa7cac1bf53c2.zip.