watchOS 6.0 (build 17R5556d) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2019-08-07T17:13:48Z. The update package is 685.27 MB. This is a delta (partial) update that requires 5.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 477ba0e0d78790791fafd71a1321363d54deb2c3.zip.