watchOS 6.0 (build 17R5532f) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2019-07-17T17:42:02Z. The update package is 677.06 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: 94392d15ef2e6044ea6585f055aef2890254d946.zip.