watchOS 6.0 (build 17R5575a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-08-27T17:31:31Z. The update package is 687.54 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: 398f16bf04717d79c6692a6f9bba4f30f0cc949c.zip.