watchOS 6.0 (build 17R5566a) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-08-15T17:17:37Z. The update package is 750.41 MB. This is a delta (partial) update that requires 5.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 77fc2470ac8eddad4c2ebdf2848a8ce1c266198b.zip.