watchOS 6.0 (build 17R5571a) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2019-08-21T17:10:24Z. The update package is 684.88 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: 41099c19888adbcd87c4cc16497aa6f3492082c8.zip.