watchOS 6.0 (build 17R5556d) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-08-07T17:14:59Z. The update package is 687.9 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: 35c7d5241751844aaacaf154d8bec2747785fbc0.zip.