watchOS 6.1 (build 17S5076a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-10-16T17:13:54Z. The update package is 747.47 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: 22f4ae97b6d4d0e19ede82df7374509da18925d7.zip.