watchOS 6.0 (build 17R5575a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-08-27T17:31:24Z. The update package is 688.05 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: 32a5858991977053327e6fdf4e0ab8ece100d81d.zip.