watchOS 4.2.2 (build 15S6542) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2018-01-19T18:09:26Z. The update package is 54.37 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: ddb4415a9941d9a14fb03f236a4542612fce7955.zip.