watchOS 6.0 (build 17R5575a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-08-27T17:32:05Z. The update package is 710.06 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: eb28a9c8195d00fc0f17bff5f593b6b6c8c44447.zip.