watchOS 6.0 (build 17R5546f) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2019-07-30T17:09:26Z. The update package is 684.77 MB. This is a delta (partial) update that requires 5.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4b4a4f23365d6f7a6e93e0ea9a4f810e22d954e4.zip.