watchOS 6.0 (build 17R5571a) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2019-08-21T17:10:41Z. The update package is 687.5 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: 89c2478025ad5a9f3bc3811c228e17726f0cb1a7.zip.