watchOS 6.0 (build 17R575) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-09-11T18:35:05Z. The update package is 743.12 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: 15aa0f2296f86fc9a0356235c9bba59979b6ee02.zip.