watchOS 6.0 (build 17R5521e) is an official Apple over-the-air update for the Apple Watch Series 4 (40mm), released on 2019-07-02T18:10:42Z. The update package is 661.21 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: 780a9ae01c63bd648c5dafa6a8d86722480d25f5.zip.