watchOS 6.0 (build 17R5575a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2019-08-27T17:29:45Z. The update package is 748.1 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: c6b36edba1b9d4b169ecb23af61fbf1c0e360ef9.zip.