watchOS 5.1.2 (build 16S5042a) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2018-11-07T21:14:38Z. The update package is 126.24 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: 035c87616e8f7d4d2ed81603acdfddfa0e5d8a0c.zip.