watchOS 6.0 (build 17R5507l) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-06-17T17:12:36Z. The update package is 657.09 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: 6fa2646ac15c0c586f84a37121129bebfd8b5553.zip.