watchOS 6.1 (build 17S5054e) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-09-23T17:04:43Z. The update package is 685.85 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: 055d33b486ef8cc9efdaadcad5cfcd791c73f900.zip.