watchOS 6.0 (build 17R5575a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-08-27T17:32:07Z. The update package is 709.91 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 35c70702c58537a1eff8fae3afbcf27f54733c6f.zip.