watchOS 4.1 (build 15R5823c) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-09-27T16:58:52Z. The update package is 542.56 MB. This is a delta (partial) update that requires 3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7f132815c8e2f71a2bbd470a0629fbbe8bacacf7.zip.