watchOS 6.0 (build 17R5571a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-08-21T17:11:50Z. The update package is 688.81 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: e8bb03c8e85d90762399bcdc8661fa86ec7e9812.zip.