watchOS 6.1 (build 17S5076a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-10-16T17:13:34Z. The update package is 724.94 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: 04777df5de6f771daef80b41c7d6ccd2a4d998fd.zip.