watchOS 6.0 (build 17R5521e) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-07-02T18:10:19Z. The update package is 727.56 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: 86d0dd70b04adfbf3550326455da642af988f628.zip.