watchOS 4.2.2 (build 15S5536a) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2018-01-03T18:21:57Z. The update package is 52.16 MB. This is a delta (partial) update that requires 4.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 2c88cc36f97ca9b6a325f0b596ed97ad0c408a25.zip.