watchOS 6.0 (build 17R575) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-09-11T18:36:14Z. The update package is 784.48 MB. This is a delta (partial) update that requires 5.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5002ec7a37e9953a5959f5e364c127e54d18c943.zip.