watchOS 4.1 (build 15R5835d) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-10-09T17:04:38Z. The update package is 548.11 MB. This is a delta (partial) update that requires 3.2.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 209928b588de6483300599153e440098d144e9dc.zip.