watchOS 4.2.2 (build 15S542) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2018-01-19T18:08:51Z. The update package is 181.12 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: 3fd0eea15ef774e9d8b0ba5a48d0fdebd19f1717.zip.