watchOS 4.2.2 (build 15S5536a) is an official Apple over-the-air update for the Apple Watch (38mm), released on 2018-01-03T18:21:53Z. The update package is 30.99 MB. This is a delta (partial) update that requires 4.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a4133570fcb83c5d8d575f250c328e3fb10fd61e.zip.