watchOS 6.0 (build 17R5507l) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-06-17T17:11:51Z. The update package is 718.25 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: 72857861a407f230f1a68c3b951c1418dc6dc80a.zip.