watchOS 6.0 (build 17R5571a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2019-08-21T17:10:51Z. The update package is 738.39 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: 37fdbea158c038ba9bac133e5b7792768a939538.zip.