watchOS 6.0 (build 17R5566a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-08-15T17:19:06Z. The update package is 710.83 MB. This is a delta (partial) update that requires 5.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 37fbfbcf1baf286d24e72021151e0ba0400990c2.zip.