watchOS 6.0 (build 17R5571a) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-08-21T17:11:08Z. The update package is 740.42 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: 86981f5943e2e21e93b28f253d71556721252fc8.zip.