watchOS 6.1 (build 17S5083a) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2019-10-23T17:10:42Z. The update package is 727.1 MB. This is a delta (partial) update that requires 5.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 27c160490d0e745095e13322e9bb1e1a9e90aa8f.zip.