watchOS 4.2 (build 15S102) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-12-05T18:00:44Z. The update package is 792.59 MB. This is a delta (partial) update that requires 2.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: de56bc095a23fcab859fa519ac7d7ff62ed4ac67.zip.