watchOS 4.2.2 (build 15S542) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2018-01-19T18:08:12Z. The update package is 556 MB. This is a delta (partial) update that requires 3.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d6f9e7984ad114944c9aaca4949b37efdbd98288.zip.