watchOS 4.2 (build 15S5090c) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-11-06T18:02:59Z. The update package is 176.08 MB. This is a delta (partial) update that requires 4.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8dd53f735cbae180a01f1e094386f8c24f78967e.zip.