watchOS 6.0 (build 17R5556d) is an official Apple over-the-air update for the Apple Watch Series 4 (40mm), released on 2019-08-07T17:14:54Z. The update package is 532.76 MB. This is a delta (partial) update that requires 6.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 42c32bdeee1e30a01e3bdb317f008d3ec035acc6.zip.