watchOS 4.2 (build 15S5090c) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-11-06T18:03:00Z. The update package is 133.07 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: 811b8f262c6fa852f186323065832103e0f218db.zip.