watchOS 4.2.2 (build 15S542) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-01-19T18:09:28Z. The update package is 187.09 MB. This is a delta (partial) update that requires 4.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 67fbf910cf49c34d458b9df3ecd5c74052621585.zip.