watchOS 6.0 (build 17R5521e) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2019-07-02T18:10:05Z. The update package is 673.88 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: f0b1b78459dc8fa817b78dc206a54bb250778069.zip.