watchOS 6.1 (build 17S5076a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2019-10-16T17:12:52Z. The update package is 775.99 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: 613b2cea94196f8594d56162071629a46fb815a8.zip.