watchOS 6.0 (build 17R5556d) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2019-08-07T17:13:50Z. The update package is 684.69 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d40bfc9aff0b88cb2e6243d2855f3d8f1f27f23c.zip.