watchOS 4.2 (build 15S5102b) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-11-17T18:17:00Z. The update package is 132.76 MB. This is a delta (partial) update that requires 4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 45a8af605db964ffe855852c8fbe40480fd68f6c.zip.