watchOS 6.1 (build 17S5059e) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-10-02T17:11:16Z. The update package is 712.08 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: bc83c76ad22de880aa302bc07f5d75f188609209.zip.