watchOS 6.1 (build 17S5059e) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-10-02T17:10:19Z. The update package is 744.33 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: 8401e02b5ecfaf7a15ec1146dd2280643615bd02.zip.